You are presented with the question "What breathes by pulling air into the lungs?" and the following answer choices: 
- humans
 - animals
 - bears
 - sponges
 - mammals
 - bacteria
 - goats
 - oxygen

Now knowing that mammals breathe with the help of a diaphragm and when the diaphragm moves down, air is pulled into the lungs, choose the best answer.


 

     mammals    