Which one is NOT a prezygotic barrier to successful reproduction? (i.e. all of them are prezygotic barriers except one) reproductive/genital parts do not match appropriately chromosome mis-match so...

Which one is NOT a prezygotic barrier to successful reproduction? (i.e. all of them are prezygotic barriers except one) reproductive/genital parts do not match appropriately chromosome mis-match so the offspring are sterile mutation in courtship rituals mutations in the timing of reproduction