Male Frogs Give Calls That Attract Female Frogs to Approach

Male frogs give calls that attract female frogs to approach and mate. Researchers examined mating calls of closely related tree frogs in South America. What outcomes can occur where the ranges of two species overlap?

A) A stable hybrid zone will form if hybrids are better adapted to the area of overlap than either parent species is.
B) Species will continue to diverge and be isolated by behavioral or genetic mechanisms.
C) The species will interbreed, eventually fusing over time.
D) All of the above are possible outcomes.
E) None of the above are a possible outcome.