Fact 1: Running water is better able to dissolve oxygen and nutrients than standing water.

Fact 2: Water is made up of H2O molecules.

Given the two facts above, answer the question "what dissolves oxygen better when running than standing?" with the following options: 
- H2O
 - NaCl
 - pH
 - CO2
 - CO 2
 - O2
 - O3
 - H20


 

 H2O        