Tail length in mice varies within a population. scientists observed change in the distribution of tail lengths in a mouse population over time. at the genetic level, what has most likely happened to the allele for the shortest tail lengths?

a the allele changed from being dominant to being recessive.
b the allele changed from being autosomal to being sex-linked.
c the allele became less frequent than the alleles for longer tail lengths.
d the allele began to code for long tail lengths instead of the shortest ones.