Examine This Close-Up of the Placenta (On the Left of the Figure)

Examine this close-up of the placenta (on the left of the figure) .
Why do the chorionic villi have the shape of a tree?

A) The branches of the chorionic villi create a large amount of surface area for exchange of nutrients and gases between maternal and fetal blood.
B) The branches of the chorionic villi allow blood to flow back and forth between the capillaries of the mother and her fetus more rapidly.
C) The branches of the chorionic villi create more locations where fetal capillaries can fuse directly with maternal capillaries.
D) The branches of the chorionic villi create more surface area for the production of the amniotic fluid.