You are presented with the question "When many muscles contract a little bit, simultaenous, it produces:" and the following answer choices: 
- forces
 - heat
 - cold blooded
 - sweat
 - electrical energy
 - Energy
 - pain
 - thermal displacement

Now knowing that shivering occurs when many muscles contract a little bit all at once and heat production is increased by shivering and non-shivering thermogenesis , choose the best answer.


 

  heat       