OG4

OG4. The only way for growers to salvage frozen citrus is to process them quickly into juice concentrate before they rot when warmer weather returns.
(A) to process them quickly into juice concentrate before they rot when warmer weather returns
(B) if they are quickly processed into juice concentrate before warmer weather returns to rot them
(C) for them to be processed quickly into juice concentrate before the fruit rots when warmer weather returns
(D) if the fruit is quickly processed into juice concentrate before they rot when warmer weather returns
(E) to have it quickly processed into juice concentrate before warmer weather returns and rots the fruit
For parallelism, the linking verb is should link two infinitives: The only way to salvage ... is to process. Choice A begins with an infinitive, but the plural pronouns them and they do not agree with the singular noun citrus. Choices B, C, and D do not begin with an infinitive, and all present pronoun errors: the plural pronouns cannot grammatically refer to citrus or fruit, nor can they refer to farmers without absurdity. The best choice, E, has parallel infinitives and uses fruit to refer unambiguously to citrus. E also expresses the cause-and-effect relationship between the return of warmer weather and the rotting of the fruit; A, C, and D merely describe these events as contemporaneous.
ETS官方解释A不对的理由是 citrus是个单数名词，不能用they和them，但我们看各种词典，包括老美的W_M，上面都说citrus的复数形式有2种，citrus或者citruses，因此citrus在这里完全可以被理解为复数。
当然E是没有任何问题的，尤其是最后用了fruit指代非常清楚。
个人认为A的错误主要不再citrus的单复数问题，而在rot应该用被动语态，warmer weather 师citrus腐烂了，warmer weather rot citrus，从E中就可看出。不知各位意见如何？