You are presented with the question "Conserving what can be used for survival in a dry environment?" and the following answer choices: 
- bamboo
 - Collagen
 - root
 - sodium
 - cellulose
 - energy
 - salinity
 - Conifers

Now knowing that conserving water can be used for survival in a dry environment and conservation of water follows conservation of sodium, choose the best answer.


 

    sodium     