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SAT Reading and Writing

Command of Evidence

Command of Evidence is a skill in the Information and Ideas domain of the Digital SAT Reading and Writing section. These are practice questions on it, and each answer choice comes with an explanation of why it is right or wrong.

15 questions. After every answer you’ll see why each choice is right or wrong, not just the one you picked.

Round length
Difficulty (none selected means all)

Sample questions

Open a question to see the answer choices and the correct answer.

A beekeeper noticed that hives placed near fields of flowering clover produced more honey on average than hives placed near fields of flowering sunflowers. The beekeeper hypothesizes that bees foraging on clover flowers collect nectar more efficiently than bees foraging on sunflower flowers. Which finding, if true, would most directly support the beekeeper's hypothesis?
  1. A. Sunflower fields near the hives were treated with a pesticide earlier in the season.
  2. B. Local beekeepers report that clover honey generally sells for a higher price than sunflower honey.
  3. C. Bees observed foraging on clover flowers complete each nectar-collecting visit in less time, on average, than bees observed foraging on sunflower flowers. ✓
  4. D. Clover fields near the hives covered a much larger total area than the sunflower fields did.

Correct answer: C. Faster nectar-collecting visits on clover would directly support the claim that bees forage more efficiently on clover than on sunflowers.

A city's transportation department tracked the average daily number of bicycle-share rentals in four consecutive years after a network of protected bike lanes was completed: Year 1, 420 rentals; Year 2, 610 rentals; Year 3, 890 rentals; Year 4, 905 rentals. A transportation planner claims that ridership growth was fastest in the year immediately following the bike lanes' completion and slowed considerably by the fourth year. Which choice most effectively uses the department's data to complete the planner's claim: "For example, the increase in average daily rentals from Year 1 to Year 2 was ______, while the increase from Year 3 to Year 4 was only ______."
  1. A. 15 rentals ... 190 rentals
  2. B. 280 rentals ... 190 rentals
  3. C. 610 rentals ... 905 rentals
  4. D. 190 rentals ... 15 rentals ✓

Correct answer: D. The increase from Year 1 to Year 2 is 610 − 420 = 190 rentals, and the increase from Year 3 to Year 4 is 905 − 890 = 15 rentals, correctly showing growth slowing over time.

A nutrition researcher claims that participants who drank a glass of tart cherry juice each night fell asleep faster than they did before starting the regimen, and attributes this to a natural compound in tart cherries called melatonin. Which finding, if true, would most directly undermine the researcher's explanation for the participants' improved sleep?
  1. A. Participants in a separate control group who drank a similarly sweet, melatonin-free juice each night also fell asleep just as quickly as the tart cherry group did. ✓
  2. B. Tart cherries contain several vitamins in addition to melatonin.
  3. C. The study lasted for eight consecutive weeks.
  4. D. Participants who drank tart cherry juice reported enjoying its flavor more than other juices.

Correct answer: A. If a melatonin-free juice produced the same improvement, melatonin specifically cannot be what explains the faster sleep onset, undermining the researcher's proposed explanation.

A researcher hypothesizes that houseplants placed near office windows improve employees' reported job satisfaction primarily by increasing natural light exposure in the workspace, rather than through any other effect of the plants themselves. Which finding, if true, would most directly support the researcher's hypothesis?
  1. A. Employees near windows with sheer curtains that blocked plants but preserved similar light levels reported job satisfaction gains nearly identical to those near windows with plants. ✓
  2. B. Employees near windows with plants reported significantly higher job satisfaction than employees in windowless offices without plants.
  3. C. Offices with the most plants per square foot had the highest reported job satisfaction scores overall.
  4. D. Employees who could see plants from their desks reported feeling calmer during stressful workdays.

Correct answer: A. Correct — this finding isolates light from plant presence directly, showing that light alone produces the same benefit, which is exactly what the light-specific hypothesis requires.

A student is writing about how sleep duration relates to reaction time. Her notes include this data from a lab study: participants who slept 5 hours averaged a reaction time of 320 milliseconds; those who slept 6 hours averaged 290 milliseconds; those who slept 7 hours averaged 255 milliseconds; and those who slept 8 hours averaged 250 milliseconds. Which choice most effectively uses data from the study to support the claim that additional sleep provides diminishing returns on reaction time?
  1. A. Participants who slept 8 hours had the fastest average reaction time of any group in the study.
  2. B. Reaction time improved by 30 milliseconds when average sleep rose from 6 to 7 hours, but only by 5 milliseconds when it rose from 7 to 8 hours, showing each added hour helped less than the one before. ✓
  3. C. Reaction time was 320 milliseconds at 5 hours of sleep and 250 milliseconds at 8 hours of sleep.
  4. D. Participants who slept only 5 hours had noticeably slower reaction times than all other groups.

Correct answer: B. Correct — this choice directly compares the size of successive improvements and shows that the improvement shrinks as sleep increases, which is precisely what diminishing returns means.