You are presented with the question "What is a cactus stem used to reserve?" and the following answer choices: 
- dishwater
 - ocean water
 - Water
 - hydration
 - moisture
 - cactus fruit
 - nutrients
 - moist towels

Now knowing that acactus stem is used for storing water and moisture is stored in the spongy stem or root systems of the cactus during rainfall, choose the best answer.


 

     moisture    