You are presented with the question "the ultimate aquatic organism has a circulatory system with a how many chambered heart.?" and the following answer choices: 
- ligt
 - moss
 - Frog
 - tube
 - clam
 - two
 - size
 - Aves

Now knowing that fish have a circulatory system with a two-chambered heart and fish Fish are the ultimate aquatic organism, choose the best answer.


 

      two   