In a Large Population of Plants, Notches in the Leaves

Multiple Choice

In a large population of plants, notches in the leaves are caused by a dominant allele N and lack of notches by a recessive allele n. Over many generations the proportion of plants in the population with notched leaves increases. What is the most likely cause?

A) Dominant alleles generally increase in frequency over time.
B) The recessive alleles were all masked by the dominant alleles.
C) Directional selection favored plants with notched leaves.
D) Genetic drift caused a steady movement toward a greater proportion of plants with notched leaves.