Bunuel wrote:
As litigation grows more complex, the need that experts explain technical issues becomes more apparent.
(A) that experts explain technical issues becomes
(B) for experts to explain technical issues became
(C) for experts to explain technical issues becomes
(D) that technical issues be explained by experts became
(E) that there be explanations of technical issues by experts has become
simple present tense show an event which exists indefinitely , before, in , and , after speech time. also, simple present show an event which exists at the moment of speech.
so, past tense "became" can not be fit with "as".
regarding present perfect in choice E. present perfect show an event happening in a time frame until present. so, present perfect can not fit with a point of time at present or an event existing before , in, and after the speech time. so, choice E is gone. I do recommend you review present perfect in grammar books because this tense can not be explained in a few lines inhere. non native can not explain this tense to us fully. I am not focusing on grammar . I am still focusing on meaning. but tense error is meaning error and, so, is important on gmat. dont fall into trap of leaning grammar rules.
we need to fully understand basic tenses, simple present, simple past and past perfect to solve this problem. these tense is basic and we can understand these tense by reading good grammar book . but dont read too much, gmat dont test minor points of grammar. it tests hard and basic points of grammar.
need to do, need for somebody to do , and need of somthing, are good idioms. choice A is gone.