I believe D is correct. If D is true, then it means people make not be healthier on average if they take Vitamin C.
The article argues that taking vitamin C tends to make people healthier on average.
A - Irrelevant as it does not address the argument above.
B - Even if true, it supports the argument that taking Vitamin C does make one healthier (although there are other ways to do it).
C - Even if true, it does not deny that taking vitamin C does make people healthier on average.
E - Supports the argument.
Newspaper article: People who take vitamin C supplements tend to be healthier than average. This was shown by a study investigating the relationship between high doses of vitamin C and heart disease, which showed that people who regularly consume high doses of vitamin C supplements have a significantly lower than average risk of heart disease.
Which one of the following, if true, would most weaken the argument in the newspaper article?
(A) Vitamin C taken in the form of supplements has a different effect on the body than does vitamin C taken in food.
(B) The reduction in risk of heart disease due to the consumption of vitamin C is no greater than the reduction due to certain other dietary changes.
(C) Taking both vitamin C supplements and vitamin E supplements lowers one’s risk of heart disease far more than does taking either one alone.
(D) High doses of vitamin C supplements tend to reduce slightly one’s resistance to certain common infectious diseases.
(E) Taking vitamin C supplements has been found to lower one’s risk of developing cancer.