You are presented with the question "What causes ice sculptures to turn to liquid? " and the following answer choices: 
- UV rays
 - Snow
 - salt and water.
 - Heat energy
 - air cools
 - kinetic energy
 - Subzero temperatures
 - Water expanding

Now knowing that melting means changing from a solid into a liquid by adding heat energy and ice Sculptures melt away, choose the best answer.


 

    Heat energy     