Help please asap Directional selection differs from stabilizing selection in that:

a. Directional selection favors one extreme phenotype, whereas stabilizing selection favors intermediate over extreme phenotypes

b. Directional selection requires new mutations whereas stabilizing selection uses existing variation

c. Directional selection operates only in small populations, whereas stabilizing selection only works in large populations

d. they both do nothing, these are terms I made up while writing this retake