You are presented with the question "What is treating water to remove harmful substances done before?" and the following answer choices: 
- vaporization
 - bacteria
 - evaporation
 - hydration
 - dangerous
 - Frogs
 - Relieve pain
 - a pathogens

Now knowing that treating water is used to remove harmful substances before drinking and hydration is maintained by drinking a lot of fluid, choose the best answer.


 

    hydration     