You are presented with the question "What happens to metal when heat passes through it?" and the following answer choices: 
- It sheds a layer of rust
 - kinetic energy
 - It expands
 - It turns into gold
 - electricity
 - mechanical
 - sweating
 - It contracts

Now knowing that when metal conducts heat , that metal expands and conduction is the passing of heat through a medium, choose the best answer.


 

   It expands      