Complete Question Explanation
Evaluate the Argument-#%. The correct answer choice is (B)
To properly attack an Evaluate the Argument question, first you must identify the argument itself. Here, the author is making a causal argument: eating garlic reduces cholesterol and triglycerides and thus helps to reduce the risk of heart disease. To evaluate the strength of a causal argument, it is important to know if any alternate causes could be present (if not, then the argument is strengthened; if so, the argument is dramatically weakened). So, while you know that the group taking garlic pills saw more significant effects on cholesterol and triglycerides than the other group, you cannot know if garlic was the true cause unless you know about other potential causes as well (diet in this case).
Answer choice (A): The argument is only about what effect the garlic tablets have, not about their availability.
Answer choice (B): This is the correct answer choice. Applying the Variance Test: the two groups had the exact same diet, or the two groups had very different diets. If the diets were the same, then it is more likely that the garlic could have produced the observed effect (author’s argument would be strengthened). However, if the diets were very different then the dietary choices could have produced the effect (the argument in the stimulus would be weakened)
Answer choice (C): Since the argument is about patients taking the garlic tablets for four months, information about people taking the pills for less than four months would not be relevant.
Answer choice (D): There are two problems with this answer choice: you do not know the amount of garlic that was taken (“large”?), and the argument is about the effect of garlic, not about how all of the patients tolerated it. So regardless of whether large amount of garlic were well tolerated by all of the patients or not, the conclusion is not affected.
Answer choice (E): The manufacturer’s advertising is completely irrelevant to the conclusion presented.