You are presented with the quiz "Birds are vertebrate endotherms with what?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "birds are endothermic tetrapod vertebrates" and "legs define Tetrapods". So, what's the best answer to the question?
Choose your answer from: (a). fat; (b). Energy; (c). legs; (d). like some sharks; (e). Tail; (f). invertebrates; (g). arms; (h). four;
Answer:
(c).