[求助]请教LZM E2-16

E2-16

Research during the past several decades on the nature of language and the processes that produce and make it understandable has revealed great complexity instead of underlying simplicity.

A.      that produce and make it understandable has revealed great complexity instead of underlying simplicity

B.      of producing and understanding it have revealed not underlying simplicity but great complexity

C.      by which it is produced and understood has revealed not underlying simplicity but great complexity

D.     by which it is produced and understood have revealed great complexity rather than underlying simplicity

E.      by which one produces and understands it have revealed great complexity instead of underlying simplicity

为什么答案选择A而不是C呢？他给出的解释说主动和被动的关系，可是同时不是用rather than而不是instead of吗？这种时候依据什么标准呢？

应该是改变原文语态错误比较大的关系吧，

en, seems so if  you explain in this way. thanks a lot.

and hope you'll get your satisfied score