Frogs have a _-chambered heart.\nOptions:\n- (A) alveoli\n- (B) organ\n- (C) ovaries\n- (D) oxygen\n- (E) edible\n- (F) three\n- (G) nektar\n- (H) CO 2
Let's think step by step below.
(F)
Amphibians have a relatively complex circulatory system with a three-chambered heart.

All frogs are amphibians.

Frogs have a three-chambered heart.

.

So, the answer is (F)