Fact 1: An animal requires air for survival.

Fact 2: Oxygen Oxygen is in the air we breathe.

Given the two facts above, answer the question "What do animals require for survival?" with the following options: 
- food
 - glycogen
 - Lithium
 - water
 - sugar
 - Helium
 - Aluminum
 - Oxygen


 

        Oxygen 