You are presented with the question "What do amphibians pump around the body in a complex manner?" and the following answer choices: 
- SO2
 - food
 - Energy.
 - oxygen
 - Energy
 - thoughts
 - blood
 - water

Now knowing that amphibians have a relatively complex circulatory system with a three-chambered heart and blood is pumped around the body by a heart , choose the best answer.


 

       blood  