Feifei 94 请教

94. When 100 people who have not used cocaine are tested for cocaine use, on average only 5 will test positive. By contrast, of every 100 people who have used cocaine 99 will test positive. Thus, when a randomly chosen group of people is tested for cocaine use, the vast people is tested for cocaine use, the vast majority of those who test positive will be people who have used cocaine.

A reasoning error in the argument is that the argument

(A) attempts to infer a value judgement from purely factual premises

(B) attributes to every member of the population the properties of the average member of the population

(C) fails to take into account what proportion of the population have used cocaine

(D) ignores the fact that some cocaine users do not test positive

(E) advocates testing people for cocaine use when there is no reason to suspect that they have used cocaine

这题的答案应该是什么呀？我选的是A。有没有人愿意帮我解答一下。

Thank you for the clarification.

question for C. the problem says" the vast...  the vast"

for a given percentage of ppl who use cocaine, no matter the sample size, the percentage of ppl who tested positive and use cocaine is a constant. right?