N contrast to ectotherms, endotherms A. are more efficient in warm environments. B. need less to eat. C. create and conserve body heat better. D. maintain a lower metabolic rate.

The correct answer is C. create and conserve body heat better. Endotherms is just a scientific way of the common phrase that animals are warm-blooded, meaning they're not like lizards or snakes. Body heat is mostly produced as a result of metabolic activities, but there are animals with specific mechanisms for cases when there's no heat or in really cold areas.