Penguins,seals,and Tuna Have Body Forms That Permit Rapid Swimming Because

Penguins,seals,and tuna have body forms that permit rapid swimming because

A) all share a common ancestor at some point in the past.
B) all of their bodies have evolved to allow rapid swimming because of their predator/prey interactions over time.
C) the shape is a convergent evolutionary solution to the need to reduce drag while swimming.
D) this is the only shape that will allow them to maintain a constant body temperature in water.