Health association: In certain studies, most volunteers who used to eat meat have permanently excluded meat form their diets and now eat only vegetables and fruits. These volunteers suffered no ill effects and many even prefer the new regimen. So people who eat meat can change their diets to meatless ones and not suffer as a result.
Critic: Participants in these studies were all favorably disposed to the substitution before they started, and even so, many of them failed to make a complete transition to a vegetarian diet.
The critic's response would most seriously call into question which of the following conclusions, if that conclusion were drawn on the basis of the evidence given by the health association?The health association says that most volunteers who switched from meat to only vegetables and fruits suffered no ill effects, so people can make that switch without suffering. The critic attacks that evidence by saying the volunteers were already
favorably disposed to vegetarianism, and even then many failed to make the full transition.
So the critic mainly challenges any broad conclusion about how easily most ordinary people would be able to make the switch.A. The diets of most people who eat meat would be improved if those people ate only vegetables and fruits instead.
The critic does not directly attack this. The response is about whether people can successfully make the transition, not about whether such a diet would improve health.
B. Among those who attempt to exclude meat from their diets, the more favorably disposed to the meatless regimen a person, the more likely that person is to succeed in the attempt.
This is not undermined. If anything, the critic’s point is consistent with it: even people already favorably disposed had trouble, which suggests disposition matters.
C. The number of people who have adopted a strictly vegetarian diet has increased in the last few years.
The critic says nothing about trends over time, so this is not called into question.
D. Participants in the study who failed to make the transition to a vegetarian diet did not regret the attempt.
The critic gives no information about regret, so this is unsupported but not specifically challenged.
E. Most people, if told by their physicians to exclude meat from their diets and eat only vegetables and fruits, would succeed in doing so.
This is the best answer. The critic directly weakens this kind of conclusion. If even volunteers who already liked the idea often failed, then it is doubtful that
most people in general would succeed just because a physician told them to.
Answer: (E)