Fact 1: Most people can survive only a few days without water.

Fact 2: Water is everywhere H20.

Given the two facts above, answer the question "Most people can survive only a few days without what?" with the following options: 
- carbon dioxide
 - oxygen
 - h2o
 - H20
 - NaCl
 - CO2
 - soda
 - urea


 

    H20     