You are presented with the question "What can contract a little bit all at once as a short term adjustment to the cold?" and the following answer choices: 
- that metal
 - muscles
 - Weight
 - stomach
 - mammals
 - atoms
 - ligaments
 - sweating

Now knowing that shivering occurs when many muscles contract a little bit all at once and almost all birds use shivering as a short term adjustment to the cold, choose the best answer.


 

  muscles       