Fact 1: Cells cannot survive without oxygen.

Fact 2: Survival is to live, to live means hope.

Given the two facts above, answer the question "Cells cannot live without what commonly occuring element found on Earth?" with the following options: 
- Air
 - matter
 - Light
 - fossil fuel
 - oxygen
 - carbon
 - sunlight
 - water


 

     oxygen    