Q: You are presented with the quiz "How do mammals generate heat?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "mammals generate heat mainly by keeping their metabolic rate high" and "faster metabolism means more calories consumed, and usually, weight loss". So, what's the best answer to the question?

Possible answers: (A). freezing (B). Ice cubes (C). layers of fat (D). Taking pictures (E). with their fur (F). energy of moving objects (G). Consuming calories (H). Movement of an air mass
The answer is:
(G).