Fact 1: Thyroid hormones increase the rate of metabolism in cells throughout the body.

Fact 2: Thyroid hormone regulates the body's metabolism.

Given the two facts above, answer the question "What regulates metabolism?" with the following options: 
- water
 - mammals
 - food
 - sweating
 - hormones
 - lungs
 - sleep
 - Chlorophyll


 

     hormones    