A female fish may lay thousands of eggs at once. Which additional statement about fish is most useful for explaining how fish species can evolve by natural selection?

A. All of the fish eggs are genetically identical with one another and with the female parent fish.
B. The environment cannot support unlimited growth of the fish population, so only some fish eggs will mature to adults.
C. After the female fish lays a clutch of eggs, neither parent tends to or cares for the eggs or offspring.
D. Fish eggs will develop into embryos only if they are fertilized by sperm from the male fish.