GMAT Critical Reasoning (CR) | Re: Scientists have several rival theories on the causes of

Getting lots of requests for expert replies on this one, and I have to agree with Kyle here: (C) is a pretty lousy answer, since the passage already basically tells us we need deep sleep for the healthy function of the nervous system.

Usual disclaimers apply here: even the best test-prep companies have a really, really hard time copying the actual exam. And this one misses pretty badly, in my opinion.

So don't lose sleep over it, friends! After all, you need sleep -- deep sleep! -- for the healthy
...

---