You are presented with the question "What turns a liquid into a solid?" and the following answer choices: 
- The bending of a ray of light
 - decreasing liquid
 - reducing heat energy
 - Warm air moving into cold air
 - movement of tectonic plates
 - keeping current temperature
 - adding more heat
 - evaporation

Now knowing that freezing means changing from a liquid into a solid by reducing heat energy and liquid water holds a huge amount of heat energy and resists changes of state to solid or gas, choose the best answer.


 

   reducing heat energy      