Which of these provides the best evidence that an environmental change has occurred?

What’s the student’s scientific question

Nkentucky, intoxicating beverages (beer, whiskey, wine, etc.) are involved to some extent in approximately % of collisions fatal to pedestrians.

Whenever diploid populations are in hardy-weinberg equilibrium at a particular locus a) the allele's frequency should not change from one generation to the next, but its representation in homozygous and heterozygous genotypes may change. b) natural selection, gene flow, and genetic drift are acting equally to change an allele's frequency. c) this means that, at this locus, two alleles are present in equal proportions. d) the population itself is not evolving, but individuals within the population may be evolving.