« on: November 13, 2007, 11:06:27 PM »
I'm not exactly sure I understand what you were trying to say but let me just explain what I see in the stimulus and maybe that'll help you.
There was a study conducted about some drug P. One of its side effects is that it lowers cholesterol, and additionally, one-third who took it had fewer nonfatal heart attacks and one-third fewer deaths from coronary disease (as compared to those who did not take drug P).
The results from the study above match another different study that was once conducted. In that study, it was concluded that those who have heart disease often have higher than average cholesterol levels.
Therefore, we can conclude that lowering cholesterol reduces the risk of heart disease.
The assumption the argument makes is that in the first study the reason that drug P lowered heart disease was because it helped lower cholesterol. But couldn't drug P have done something else that could have reduced the risk of heart disease?
Answer choice D isn't a flaw because the conclusion "shouldn't" have to focus on the relation between pravastatin and cholesterol levels. Like you said, the stimulus already mentions the relationship between Pravastatin and cholesterol (Pravastatin helps lower cholesterol).
As for your concern about B, you're right, the stimulus does mention that Pravastatin does reduce the effect of heart disease. But the argument is that this study helps prove that the reason Pravastatin worked was because it lowered cholesterol which then helped lower heart disease. It forgets the possibility that Pravastatin could do something else that helps lower heart disease that is independent of just reducing cholesterol.