GMAT Sentence Correction (SC) | Re: Reptiles, by drawing their body heat directly from

Reptiles, by drawing their body heat directly from the Sunrather than burning calories to generate it , can survive on ten percent of the nourishment that a mammal of similar size would normally require

A) rather than burning calories to generate it
B) rather than the generation of body heat by burning calories
C) and not from generating it by burning calories
D) instead of by burning calories for generating it
E) instead of body heat generated by burning calories