You are presented with the question "what have a circulatory system with one or two hearts that pump blood" and the following answer choices: 
- a fish
 - aorta
 - bacteria
 - animals
 - clams
 - plants
 - sharks
 - Birds

Now knowing that mollusks have a circulatory system with one or two hearts that pump blood and clams are mollusks that live in the sea or in freshwater, choose the best answer.


 

     clams    