Chance Fluctuations of Allele Frequencies in the Gene Pool of a Population

Chance fluctuations of allele frequencies in the gene pool of a population:

A) come about due to random events at the population level.
B) illustrate the operation of polygenes.
C) illustrate the phenomenon of incomplete dominance of the allele for normal hemoglobin.
D) come about due to random events at the individual level.
E) indicate that the species is endangered.