In contrast to ectotherms, endotherms a. maintain a lower metabolic rate. b. create and conserve body heat better. c. need less to eat. d. are more efficient in warm environments.

 B. create and conserve body heat better.

Ectotherms are cold blooded animals, which depends on external heat sources like sunlight to maintain their internal body temperature. The ectotherms include fishes, reptiles, invertebrates and amphibians. They do not require as much as food consumed by the warm blooded animals. They are unable to tolerate cold surroundings. Endotherms are warm blooded animals. These animals generate heat in their body. They increase their heat metabolism with respect to cold surrounding to maintain their internal body temperature constant. These animals are not much dependent on external heat as ectotherms are.  

Therefore, in contrast to ectotherms, endotherms create and conserve body heat better.

youre right there are