medium · SAT Reading & Writing

Marine biologists studying reef stress hypothesize that as sea-surface temperature rises above the historical average, the percentage of coral colonies exhibiting bleaching increases as well. Their data from four reef sites are shown below. Reef Site: Water Temperature Anomaly (degrees Celsius above normal), Coral Bleached (percent) Site A: +0.5, 12% Site B: +1.2, 34% Site C: +2.0, 61% Site D: +2.8, 85% Which choice most effectively uses data from the table to illustrate this claim?

1. Site D recorded the highest temperature anomaly in the study, at 2.8 degrees Celsius above the historical average.
2. Because bleaching rose from 12% at Site A to 85% at Site D, any reef exposed to a temperature anomaly greater than 2 degrees Celsius above average will suffer complete coral death.
3. At Site A, where the anomaly was only 0.5 degrees Celsius, 12% of coral was bleached, while at Site D, where the anomaly reached 2.8 degrees Celsius, 85% of coral was bleached.
4. At Site A, 12% of coral was bleached even though its anomaly of 2.8 degrees Celsius was the highest recorded, showing that bleaching actually decreases as temperatures rise.

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