You are presented with the question "When metal is warmed, the transfer of heat does what to metal?" and the following answer choices: 
- expands
 - Energy.
 - breaks
 - blossoms
 - burning
 - voltage
 - improve
 - decreases

Now knowing that when metal conducts heat , that metal expands and when a metal rod is warmed, the transfer of heat is by conduction, choose the best answer.


 

 expands        