Why is the Hardy-Weinberg equation more accurate in predicting genotypic frequencies in the short run than in the long run?

A)The equation does not take epistasis into consideration.
B)The Hardy-Weinberg equation is based on Mendel's second law of inheritance.
C)The equation can be applied only to traits determined by single genes.
D)Populations do not conform to the assumptions of the Hardy-Weinberg law.