Sperm-Egg Interactions Are Species-Specific in Sea Urchins,but Not in Mammals

Multiple Choice

Sperm-egg interactions are species-specific in sea urchins,but not in mammals.What might be one reason for this difference?

A) Other kinds of signals serve similar functions in mammals.
B) Sperm-egg recognition relies on egg cytoplasmic components in mammals.
C) Sperm have evolved to become more selective in mammals.
D) Sea urchin fertilization occurs in open ocean.