Passage Summary: Researchers gave high-cholesterol food to two groups of people with different genetic markers. One group's cholesterol levels stayed the same, but the other group's levels went up significantly.

Reasoning: In a study of two groups with different genes, a high-cholesterol diet caused a 20 percent increase in blood cholesterol for those with the Apo-A-IV-1 gene, while those with the Apo-A-IV-2 gene saw no change.

Analysis: This stimulus provides a controlled comparison that highlights a genetic correlation. We are looking for an inference that stays within the bounds of the data provided without making unwarranted causal claims about heart disease itself. The most supported statement will likely focus on the fact that the Apo-A-IV-2 gene appears to correlate with a resistance to dietary cholesterol increases, or conversely, that the Apo-A-IV-1 gene makes one more susceptible. Be wary of answer choices that generalize to the entire population or suggest that diet is the *only* factor in cholesterol levels. The data is specific to these two genes and their reaction to a high-cholesterol diet.