Acactus stem is used for storing water, and cactuses store water, serving as their own reservoirs and surviving long droughts. Given these facts, how does a cactus survive droughts among the following options:
- It becomes dormant
 - It helps them survive
 - roots and shoots
 - high humidity
 - circulatory systems
 - roots to grow
 - Holding water in the stem
 - dormant state


 

       Holding water in the stem  