<求助>陈向东一道解释题

 Studies have shown that people who rarely take antibiotics, which are antibacterial drugs, have stronger immune systems than do people who take antibiotics frequently. Yet there is no evidence that taking antibiotics weakens the immune system.

Question:Which of the following, if true, best reconciles the apparent discrepancy in teh information above?

(A) People who have strong immune systems seldom get the kinds of infectionsfor which people normally take antibiotics.
(B) People who have strong immune systems are seldom aware that their immune systems are unusually strong.
(C) People who have weak immune systems have great difficulty recovering from bacterial infections if they do not take antibiotics.
(D) Some people take antibiotics even though the antibiotics cause a variety of side effects.
(E) Some people take antibiotics frequently because their doctors prescribe antibiotics forviral infections as well as for bacterial infections.

只有A选的出来，后来一想又没法理解A为什么对了~ A算是什么思路呢？