You Are at the Aquarium Looking at a Freshwater Mammal

You are at the aquarium looking at a freshwater mammal tank and an adult manatee swims close to the glass.On his front flippers you see fingernails.What is a likely explanation for the presence of fingernails on a manatee?

A) They are analogous to human fingernails.
B) They are homologous to fish fins.
C) They are a developmental homology.
D) They are analogous to bear claws.
E) They are vestigial structures.