Directional Selection Would Be Expected to Occur If

Directional selection would be expected to occur if

A) a new allele arises by mutation that increases fitness.
B) the environment changes.
C) the population is large.
D) a new allele arises by mutation that increases fitness and the environmental changes increase the allele frequency.
E) a new allele arises by mutation that increases fitness, the environment changes and the population is large are correct.