Which animals are endotherms?

birds and mammals

fish and reptiles

amphibians and fish

reptiles and birds

The right option is; birds and mammals

Endotherms are animals that can generate and maintain a constant body temperature (heat) irrespective of their environmental temperature. The endotherms mainly include birds and mammals. If the heat generated by endotherms is more than the heat loss, they usually sweats or pants to maximize the heat loss, but if the heat loss is more than the heat generated the metabolic rate is increased or they shiver to increase their body temperature.

The answer is Birds and Mammals.