Fact 1: Fish have a circulatory system with a two-chambered heart.

Fact 2: Fish, such as tuna, is a high protein food.

Given the two facts above, answer the question "What has a circulatory system with a two-chambered heart?" with the following options: 
- salmon
 - Man
 - Toyota
 - Birds
 - koalas
 - tuna
 - sharks
 - toads


 

      tuna   