Which of the Following Is Most Analogous in Structure and Function

Which of the following is most analogous in structure and function to the circulatory systems of bony fishes, rays, and sharks?

A) the three-chambered heart of reptiles, where oxygenated and non-oxygenated blood mix in the ventricles
B) the portal systems of mammals, where two capillary beds occur sequentially, without passage of blood through a pumping chamber
C) the circulatory systems of sponges, where gas exchange in all cells occurs directly with the external environment
D) the four-chambered heart of humans, where non-oxygenated blood is pumped to the lungs from one ventricle and oxygenated blood is pumped to the body from another ventricle