Fact 1: When metal conducts heat , that metal expands.

Fact 2: When a metal rod is warmed, the transfer of heat is by conduction.

Given the two facts above, answer the question "When metal is warmed, the transfer of heat does what to metal?" with the following options: 
- expands
 - Energy.
 - breaks
 - blossoms
 - burning
 - voltage
 - improve
 - decreases


 

 expands        