請教費費邏輯 no. 120

amyhsiao

120. In Europe, schoolchildren devote time during each school day to calisthenics. North American schools rarely offer a daily calisthenics program. Tests prove that North America children are weaker, slower, and shorter-winded than European children. We must conclude that North American children can be made physically fit only if they participate in school calisthenics on a daily basis.
Which one of the following is assumed in the passage?
(A) All children can be made physically fit by daily calisthenics.
(B) All children can be made equally physically fit by daily calisthenics.
(C) Superior physical fitness produces superior health.
(D) School calisthenics are an in indispensable factor in European children’s
(E) North American children can learn to eat a more nutritious diet as well as to exercise daily.

答案是D
請問A為何不對?  

thanks.

cranberry

a说的是充分条件，d说的是必要条件，而只有必要条件合乎题目的结论。

amyhsiao

不好意思.....
可以解釋的再清楚一點嗎????