You are presented with the question "what do some plants use a stem to store?" and the following answer choices: 
- CO2
 - H20
 - RNA
 - UV
 - urea
 - Dew
 - h2o
 - rain

Now knowing that astem is used to store water by some plants and water is made up of H2O molecules, choose the best answer.


 

       h2o  