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.
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. superfically, 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

C is correct but i dont understand how this part of the statement makes sense "the human nervous system bears a superficial resemblance to a telephone system both "...the "both" in there is throwing me off. wouldnt it be more correct to leave 'both' out of the sentence? I know in this case C is the best answer...but i didnt think that was even correct...

i see your point, but, no, the sentence is fine. it has perfect parallelism, and it uses the construction 'both ... and' in an acceptable manner.

remember that the name of the game is not picking a perfect sentence; it's picking the best sentence from the available choices, which may, in the worst cases, mean that you have to pick the least imperfect sentence.

as you've said, you already recognize that choice c is the best of the lot; therefore, you should close your eyes, bite down hard, and pick it.