[求助]大全D-14

D-14.       A nutritionist studying the effects of massive doses of vitamin C found that of a group of 600 people who regularly took 1,500 mg of vitamin C daily for a year, fewer than 9 percent suffered serious cases of flu; of a group of 600 people who took 250 mg of vitamin C (the standard recommended daily allowance) daily for a year, 34 percent suffered at least one serious case of flu; and of a group of 600 people who took no vitamin C for a year (other than that found in the foods in a balanced diet), 32 percent suffered at least one serious case of flu.

Which of the following hypotheses is best supported by the evidence above?

(A) The effectiveness of vitamin C in preventing serious cases of flu increases in direct proportion to the amount of vitamin C taken.

(B) Vitamin C is helpful in preventing disease.

(C) Doses of vitamin C that exceed the standard recommended daily allowance by 500 percent will reduce the incidence of serious cases of flu by 25 percent.

(D) Massive doses of vitamin C can help to prevent serious case of flu.（D）

(E) A balanced diet contains less than 250 mg of vitamin C.

答案D为什么对？C哪里错？哎，不害怕数学，但害怕逻辑里的数学，一绕就昏

题目中说明fewer than 9%，比例超过25%