Under ideal Hardy-Weinberg conditions (very large population, random mating, no mutation, no migration, and no natural selection), how do allele frequencies change over time?

• A. They change each generation due to segregation and recombination even without other evolutionary forces.
• B. They remain constant from generation to generation.
• C. They always shift to match genotype frequencies so that $p=p^2$ and $q=q^2$ after one generation.
• D. They increase or decrease predictably toward fixation because random mating changes allele frequencies.

Answer: (B)