对于Prep2-20题的问题，请教了！

The human nervous system and a telephone system superficially resemble each other, not only because the former carries information in the form of electrical impulses and because all of its neural pathways converge in the brain and spinal cord, which together form a kind of central exchange.

(A) The human nervous system and a telephone system superficially resemble each other, not only because the former carries

(B) The human nervous system and a telephone system bear a superficial resemblance because they both carry

(C) The human nervous system bears a superficial resemblance to a telephone system both because the former carries

(D) Superficially, a telephone system resembles the human nervous system both because they carry

(E) There is a superficial resemblance between a telephone system and the human nervous system, not only because they both carry

想请问一下，PERP的解释上面说，选项B中的they没有指代，是指they不能指代之前出现的A and B这样的结构吗？我认为指代是可以的，只是后面的its限定了主语只能为The human nervous system ，不知道对否，谢谢！

自己顶up

虽然没有遇到过，但是根据GMAT的感觉，是不允许这样子指代的，至少是不推荐的

另外请问答案是C么？

这个句子的结构是：

        人的神经系统和电话系统表面上相似，因为（原因１），又因为（原因２）。

我们在原因1里面用了"former"指代人的神经系统，那么原因2里面的it就是指代the former，（也就是人的神经系统）。

如果在原因１里面用了they指代两者，那么原因2里面的it就不知道是用来指代谁了。