You are presented with the question "What can be used to remove harmful substances from water?" and the following answer choices: 
- chlorine bleach
 - Heat energy
 - evaporation
 - oxygen
 - helium
 - Electrical energy
 - hydrogen
 - Calcium carbonate

Now knowing that treating water is used to remove harmful substances before drinking and chlorine bleach is ideal for treating water, choose the best answer.


 

 chlorine bleach        