You are presented with the quiz "What does shivering generate?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "shivering occurs when many muscles contract a little bit all at once" and "shivering causes muscle contractions to warm the body". So, what's the best answer to the question?

Possible answers: (a). kinetic. (b). energy. (c). friction. (d). Energy.. (e). expels heat. (f). heat. (g). warmth. (h). rhythm.
The answer is:
(g).