Amphibians have a relatively complex circulatory system with a three-chambered heart.
All frogs are amphibians.
Frogs have a relatively complex circulatory system with a three-chambered heart.
What has a relatively complex circulatory system with a three-chambered heart?

A) frogs
B) a fish
C) salmon
D) alpacas
E) Man
F) Birds
G) sharks
H) pan