Fact 1: Absorbing energy causes objects to heat.

Fact 2: Metal expands when heated.

Given the two facts above, answer the question "Metal expands when it does what?" with the following options: 
- absorbs energy
 - electricity
 - dries
 - freezes
 - direct energy
 - Relieve pain
 - to move people
 - contracts


 

 absorbs energy        