The correct option is D Four chambered
The heart of a crocodile is different from other reptiles in that it has four chambers just like birds and mammals. Blood is sent to the lungs for gas exchange from the right and from the left ventricle it is pumped to the body. Thus, the two types of blood do not mix in the heart. However, blood is mixed as soon as it leaves the heart via a valve placed in between the right and left aorta.