一道很奇怪的逻辑题目

candy-jing

Many pregment women suffer from vitamin deficienvy, but this is freguently not due to vitamin de ficiency in their diets; most often it is because they have higher

requirements for vitamins than do the rest of the population.

The best criticism of the reasoning in the statement above is that is

A fails to specigy the percentage of pregnant women who suffer from vitamin deficiency.

B gives insufficient information about why pregnant women have higher vitamin requirements than do other groups.

C fails to employ the same reference group for both uses of the term '' vitamin deficiency''

D provides insufficient information about the incidence of vitamin deficiency in other groups with high vitamin requirements

E use '' higher requirements'' in an ambiguous manner.

答案：C

请大家帮忙解释一下这道题的解题思路？ 谢谢