AP English Language and Composition Synthesis and Multiple Sources — Worked Answer Explanations

Unit 4 · 12 questions explained

Below is a complete answer key for our AP English Language and Composition Synthesis and Multiple Sources practice questions. For each question you'll find the correct choice, a full written explanation of how to get there, and — for every wrong answer — a short note on exactly why it's tempting and where it goes wrong. Reading these straight through is one of the fastest ways to find the gaps in a unit before exam day.

Prefer to test yourself first? Take the timed Synthesis and Multiple Sources practice test and come back here to review, or head back to the Synthesis and Multiple Sources unit overview.

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Question 1 · Easy
Source A (excerpt from a city planning department report).

The Maple Avenue corridor has seen a $42%$ increase in pedestrian fatalities over the past five years, almost entirely concentrated at intersections without dedicated turn signals. Vehicle traffic volume has remained essentially flat. The planning department recommends that all five major intersections on the corridor be retrofitted with protected left-turn signals within twenty-four months.

Source B (excerpt from a letter to the editor from a Maple Avenue business owner).

I've owned the bookstore at Maple and Third for nineteen years. I am not opposed to safety improvements. But the proposal to retrofit five intersections with protected left-turns is going to slow east-west traffic so badly that customers who used to drop in on their commute will simply stop coming. The neighborhood lost two restaurants last year and a hardware store the year before that. We do not need another reason for shoppers to choose somewhere else.

Based on Sources A and B, what is the central DISAGREEMENT between them?
- A
  Whether pedestrian fatalities have increased.
  Why not A: Source B does not dispute the fatality data — only the proposed response.
- B
  Whether the proposed safety retrofit's economic side effects on local businesses are acceptable.Correct
- C
  Whether the businesses on Maple Avenue are profitable.
  Why not C: Profitability is mentioned only by Source B as context, not as a topic of disagreement.
- D
  Whether vehicle traffic volume has risen.
  Why not D: Source A states it's flat; Source B doesn't dispute that.
Explanation
Source A makes a public-safety case for retrofitting. Source B doesn't deny the safety problem — only the cost of the proposed solution. The disagreement isn't about the data but about the trade-off between safety and economic vitality.

Key takeaway
When sources differ, identify what they agree on first, then locate the specific point of divergence.
Question 2 · Medium
Based on Sources A and B, which point do BOTH sources implicitly accept?
- A
  Maple Avenue has a real pedestrian-safety problem.Correct
- B
  Protected turn signals will reduce business revenue.
  Why not B: Source A makes no claim about revenue effects.
- C
  Pedestrian traffic should be discouraged on Maple Avenue.
  Why not C: Neither source argues for discouraging pedestrian traffic.
- D
  Business loss in the area is unrelated to traffic.
  Why not D: Source B implies that traffic patterns affect business outcomes — the opposite.
Explanation
Source A documents the safety problem. Source B says 'I am not opposed to safety improvements,' implicitly accepting the underlying issue. Both agree there's a problem; they disagree on the cost of the proposed remedy.

Key takeaway
Productive synthesis starts from the shared ground — the claim both sources accept implicitly is usually where dialogue can build.
Question 3 · Medium
An essay writer wants to use both Sources A and B to argue that 'safety improvements should be implemented but designed with business impact in mind.' Which combination of evidence from the sources best supports this synthesis?
- A
  Source A's fatality data + Source B's account of business losses.Correct
- B
  Source A's fatality data + Source B's nineteen years at the bookstore.
  Why not B: Bookstore tenure doesn't directly support a business-impact concern — losses do.
- C
  Source A's recommendation alone.
  Why not C: A single source can't support a synthesis argument.
- D
  Source B's argument alone.
  Why not D: Same issue — synthesis requires multiple sources.
Explanation
The thesis has two parts (safety + business impact). The fatality data substantiates the safety part; the business-loss account substantiates the impact part. Each source contributes the evidence the other lacks.

Key takeaway
A synthesis thesis with two parts needs evidence from each source matched to the part it best supports.
Question 4 · Medium
Source C (excerpt from a researcher's testimony on screen time and adolescent sleep).

Across the studies we have reviewed, adolescents who report using screens within an hour of bedtime sleep on average $34$ minutes less per night than peers who do not. This difference is large by sleep-research standards. Two mechanisms appear most likely: (a) the light from devices delays the body's natural release of melatonin, and (b) the content itself is arousing in a way that books and television are not.

Source D (excerpt from an op-ed by a high-school principal).

The push to ban student smartphones at home is well-meaning but largely unrealistic. Even families that succeed in removing devices from the bedroom often find their children migrate to a sibling's phone or sneak the device back at $2 AM$ . We've found that schools have a tool families don't: we can ban phones during the school day, and we can use sleep-friendly assignment policies. Rather than spending political capital on a home-life intervention parents cannot consistently enforce, we should focus the conversation on school-day policies, which are within our actual control.

Which choice best describes the relationship between Sources C and D?
- A
  Source C documents a problem; Source D argues about which response is most feasible.Correct
- B
  Source C and Source D disagree about whether screen time affects sleep.
  Why not B: Source D doesn't deny the link — it questions the feasibility of one solution.
- C
  Source C and Source D both argue against smartphone bans.
  Why not C: Source C doesn't argue against bans; it documents an effect.
- D
  Source C and Source D both argue for stricter parenting.
  Why not D: Neither source explicitly argues for stricter parenting.
Explanation
Source C is empirical: it documents that screen time near bedtime correlates with less sleep. Source D doesn't dispute this — it accepts the problem and argues that the policy response should be school-side, not home-side, because home-side interventions are not enforceable. Different layers of the same issue.

Key takeaway
Sources can be related at different levels — one establishing a problem, another proposing or critiquing solutions to that problem.
Question 5 · Medium
Based on Sources C and D, an essayist arguing for school-day phone bans would MOST effectively cite which combination?
- A
  Source C's $34$ -minute sleep loss finding + Source D's argument about enforceability.Correct
- B
  Only Source D.
  Why not B: Source D's policy argument is more persuasive when paired with C's empirical stakes.
- C
  Only Source C.
  Why not C: C documents the problem but doesn't argue for any specific policy response.
- D
  Source D's enforcement claim + Source C's mention of melatonin.
  Why not D: Pairing melatonin (mechanism) with enforcement (feasibility) doesn't focus the argument as well as the bigger sleep-loss figure does.
Explanation
C provides the stakes (lost sleep is significant) and D provides the policy logic (schools can enforce what families struggle to). Together they make a focused argument: significant harm + only school can act on it = ban during school day.

Key takeaway
Combine sources by pairing one's STAKES with another's FEASIBILITY ARGUMENT for the strongest synthesis.
Question 6 · Hard
Which additional source, if added to A and B, would MOST help an essay writer adjudicate between safety and economic concerns?
- A
  A traffic engineer's report on the actual delay caused by protected turn signals at similar corridors.Correct
- B
  A list of all businesses currently operating on Maple Avenue.
  Why not B: Inventory of businesses doesn't help adjudicate; the question is about effect size.
- C
  Historical photos of Maple Avenue.
  Why not C: Photographs would not address the trade-off in question.
- D
  Census data about pedestrian commute patterns city-wide.
  Why not D: Too coarse; doesn't address effects of the specific intervention being debated.
Explanation
The unresolved empirical question is how much actual delay the retrofit would cause. A traffic engineer's report quantifying delay would let the essay writer assess whether B's worry is realistic and proportional to A's safety benefit.

Key takeaway
Identify gaps in evidence by asking: what empirical question, if answered, would settle the disagreement?
Question 7 · Hard
Based on Sources C and D, which counterargument would be HARDEST to defend using these sources alone?
- A
  That schools should ban phones during the school day.
  Why not A: Source D explicitly supports this; well-defended.
- B
  That at-home phone restrictions are highly effective if enforced consistently.Correct
- C
  That screen time near bedtime reduces adolescent sleep.
  Why not C: Source C provides direct evidence; easy to defend.
- D
  That parents face enforcement challenges at home.
  Why not D: Source D provides direct evidence for this; easy to defend.
Explanation
Neither source provides evidence that home restrictions, when actually enforced, work well. Source C measures behavior; Source D argues home enforcement is impractical. There is no source here from which to claim effectiveness of consistent home bans.

Key takeaway
Test a counterargument by asking: do my sources contain affirmative evidence for it? If not, my argument needs an additional source.
Question 8 · Hard
Based on Sources C and D, which question is NOT directly answered by either source?
- A
  Whether melatonin is suppressed by screen light.
  Why not A: Source C names this as a likely mechanism.
- B
  How school-day phone bans affect classroom behavior.Correct
- C
  Whether teen sleep duration is affected by screen time.
  Why not C: Source C provides a direct $34$ -minute finding.
- D
  Whether home enforcement of phone restrictions is reliable.
  Why not D: Source D addresses this directly.
Explanation
Source C is about sleep; Source D argues for school-day bans on enforcement grounds. Neither addresses what happens to classroom behavior under those bans — that empirical question requires a different source.

Key takeaway
Synthesis essays often need to acknowledge what the available sources DON'T cover — these are openings for further research or for hedging the conclusion.
Question 9 · Hard
Source E (excerpt from an economics blog).

Critics of remote work often point to data showing that fewer informal mentoring conversations happen in distributed teams. They're right that this is happening. They're wrong to conclude that the right response is to mandate office presence. Mandating attendance forces people to be PRESENT but does nothing to ensure they will MENTOR. Most companies that have ordered employees back find that the people in the office do the same work they did at home, just less comfortably. If the goal is mentorship, the lever is incentives for senior employees to mentor — not seating charts.

Source F (excerpt from a HR manager's industry article).

In our internal review, we found that face-to-face encounters in shared spaces accounted for a disproportionate share of all informal feedback our junior employees received. While not all in-person time leads to mentoring, almost no remote time produced equivalent moments. We don't deny that mandates fail to FORCE mentoring; we argue that they create the conditions in which mentoring can OCCUR, conditions which remote work simply does not.

Which choice best summarizes the disagreement between Sources E and F?
- A
  Whether in-person presence is sufficient for mentoring.
  Why not A: Both agree it's not sufficient by itself — F explicitly concedes this.
- B
  Whether in-person presence is necessary, even if not sufficient, for mentoring to occur reliably.Correct
- C
  Whether remote work increases productivity.
  Why not C: Neither source frames productivity as the disagreement.
- D
  Whether mentoring matters at all.
  Why not D: Both sources treat mentoring as valuable; neither questions its importance.
Explanation
Both agree presence alone doesn't guarantee mentoring. Source E concludes presence isn't the right lever (use incentives instead). Source F concludes presence is NECESSARY even though not sufficient — without it, mentoring doesn't happen. That's the precise disagreement.

Key takeaway
Distinguish necessary vs sufficient conditions — many policy disagreements turn on whether something is NEEDED versus whether it's ENOUGH.
Question 10 · Hard
Based on Sources E and F, an essay arguing for hybrid (not fully remote, not fully in-person) policies would BEST cite:
- A
  Source E's incentive lever + Source F's claim about presence creating conditions for mentoring.Correct
- B
  Source E alone, since hybrid is mostly remote.
  Why not B: Hybrid argues for some in-person time — Source F's evidence directly supports that.
- C
  Source F alone, since hybrid is mostly in-person.
  Why not C: Source E provides the incentives lever that hybrid policies still need.
- D
  Neither source supports a hybrid position.
  Why not D: Both can be drawn on for different parts of a hybrid argument.
Explanation
A hybrid policy combines partial presence (Source F's argument that it creates conditions) with incentive design (Source E's argument that mandates don't FORCE mentoring). Each source contributes a piece a pure mandate or pure remote policy would lack.

Key takeaway
Synthesis arguments for middle-ground positions can cite each side's strongest valid concern.
Question 11 · Hard
Based on Sources E and F, which finding would MOST resolve the disagreement?
- A
  Data showing that fully-remote teams with structured mentoring programs produce as much mentoring as in-person teams.Correct
- B
  Data showing remote workers are happier.
  Why not B: Happiness doesn't resolve the question of whether presence is necessary for mentoring.
- C
  Data on commute times.
  Why not C: Doesn't address the necessity-of-presence question.
- D
  Survey data showing managers prefer in-person.
  Why not D: Preference doesn't establish whether presence is actually necessary.
Explanation
Source F argues that without presence, mentoring 'does not' occur in equivalent form. If a structured remote-mentoring program achieves equivalent outcomes, that argument is refuted and Source E's incentive-lever view gains support. The empirical existence proof is the decisive test.

Key takeaway
Disagreements over necessity can be resolved by exhibiting a successful counterexample — a case where the supposedly-necessary condition is absent but the outcome occurs anyway.
Question 12 · Hard
Across all six sources (A–F), what common feature do the disagreements share?
- A
  Both parties dispute the underlying facts.
  Why not A: In each pair, the parties agree on the empirical problem and disagree on the response.
- B
  The disagreements are mostly about which response a shared problem warrants, not about the problem itself.Correct
- C
  Both parties propose the same solution.
  Why not C: Each pair has different proposed solutions.
- D
  All disagreements involve money.
  Why not D: The remote-work disagreement is not principally about money.
Explanation
A vs B agreed on safety; disagreed on cost of the proposed retrofit. C vs D agreed on sleep loss; disagreed on which institution should act. E vs F agreed on mentoring's value and that presence isn't sufficient; disagreed on whether it's necessary. In each case, agreement on the problem and disagreement on the response.

Key takeaway
Synthesis often involves disagreements about RESPONSE, not FACT. Naming the shared problem first is what makes synthesis possible.