觉得都不太正确
FACTS:
1) Vitamin E is helpful
2) Two forms of vitamin E exist
3) One form of vitamin E is alpha, on form of vitamin E is gamma
4) gamma is supplemented by typical person's diet
5) gamma should be added into supplements
17. Which of the following most logically completes the argument?
A. Any boost in the level of the alpha form in a person’s body will tend to suppress the level of the gamma form in that person’s body.
-Supplements Facts 3, 4
-contradicts fact 5, adding alpha supresses gamma, so a supplement adding alpha and gamma may cancel out!
B. The alpha and the gamma forms can easily be combined in a stable form suitable for use in vitamin supplements.
-Supplements Facts 3, 5
-easily combinable doesn't persuade one to actually do so, no benefit listed
C. There are some foods containing high levels of the gamma form that are not a part of most people’s diets.
-Contradicts fact 4, typical diet should typically include "most people's diets"
-Does not supplement fact 5
D. People who take vitamin supplements are more likely to maintain a diet containing high levels of the gamma form than are people who do not take vitamin supplements.
-contradicts fact 5, this would be an argument against adding gamma
E. In the process currently used to manufacture vitamin E supplements, the gamma form of the vitamin is actually removed as a result of steps taken to purify the alpha form.
-contradicts fact 5, argument against adding since it would either be removed, or require a new manufacturing process