Fact 1: Amphibians have a relatively complex circulatory system with a three-chambered heart.

Fact 2: All frogs are amphibians.

Given the two facts above, answer the question "What has a relatively complex circulatory system with a three-chambered heart?" with the following options: 
- frogs
 - a fish
 - salmon
 - alpacas
 - Man
 - Birds
 - sharks
 - pan


 

 frogs        