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: 
- sharks
 - pan
 - frogs
 - Man
 - Birds
 - alpacas
 - salmon
 - a fish


 

   frogs      