Someone me out with this question

Ineed to know why d is the correct answer asap

14) 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.

Fill in the blank with the best word to complete the sentence. white blood cells protect against and aid in blood clotting when injuries are sustained.