You are presented with the question "Doing what to salt water causes the water to become fresh water?" and the following answer choices: 
- watershred
 - freezing
 - Regrows it
 - migrate
 - pouring
 - heating
 - cooling
 - erosion

Now knowing that heating salt water causes the water to evaporate while the salt remains and flash evaporators are used to make fresh water from salt water, choose the best answer.


 

      heating   