Which Statement About the Evolution of Reproductive Isolation Is False

Which statement about the evolution of reproductive isolation is false?

A) Reproductive isolation evolves at about the same rate in nearly all groups of organisms.
B) Reproductive isolation can evolve gradually in the lab, even if the researchers do not directly select for it.
C) Reproductive isolation generally increases gradually with increasing genetic distance.
D) Reproductive isolation is not "all-or-nothing"; intermediate levels of reproductive isolation can be found.
E) Reproductive isolation can be man-made, and it can occur naturally.