There are several mechanisms through which reproductive isolation occurs. Which situation is an example of behavioral isolation?
A.
Mules, the offspring of a male donkey and a female horse, are unable to reproduce because they are sterile.
B.
The reproductive organs of snails only properly align when the male and female belong to the same species.
C.
Males of different, closely related species of fireflies signal for mates by flashing different light sequences.
D.
Red and purple sea urchins cannot reproduce with one another because the sperm and egg cannot fuse.