You are presented with the question "what flows with ease through soil if it's permeable?" and the following answer choices: 
- mulch
 - wind
 - NaCl
 - CO 2
 - h2o
 - oxygen
 - vapor
 - H20

Now knowing that if soil is permeable then water easily flows through that soil and h2O is the scientific name for water, choose the best answer.


 

     h2o    