If a population is in Hardy-Weinberg equilibrium,which of the following statements is correct?

A) Each allele will be present at a 50% frequency.
B) Allele frequencies can vary from generation to generation, but the average frequency must remain constant.
C) The size of the population must remain constant from generation to generation.
D) Allele frequencies must remain the same from generation to generation.
E) The rate of change of allele frequencies must be greater than 1 percent from generation to generation.