(A) increase in the incidence of malaria caused by increasing mosquito resistance against

(B) increase in the incidence of malaria because of increasing resistance of mosquitoes to

(C) increasing malaria incidence because of increasing resistance of mosquitoes to

(D) incidence of malaria increase caused by increasing mosquito resistance against（B）

(E) incidence of malaria increase because of increased mosquito resistance to

Why the answer is b not A??

Choice A can be faulted because it is not at first clear whether caused by modifies increase or malaria. Also, the proper expression here and in choice D is not resistance against but resistance to. Choice C, D, and E are wrong because the completed sentence must read 30- to 40-fold increase. In these choices, 30- to 40-fold illogically modifies incidence; furthermore, incidence of … increase in D and E is illogical. Choice B is best. The question is a little easier than the average.

B中的意思是这种病增加了,是因为蚊子的的抗药力提高了