Answer:
a. Directional selection favors one end of the phenotype distribution, whereas
stabilizing selection favors intermediate over extreme phenotypes
Explanation:
Directional selection is called directional because it favors one phenotype over another, and stabilizing selection finds a balance between phenotypes.
The answer to this is older, but it's not a proven fact even though schools teach it as if it were. It is still just a theory if you think about it with how much the earth moves, areas of rock could be complete upside down and no one would know, it would be like history in reverse.