A problem in all populations influenced by the bottleneck effect is that?

(A). A bottleneck effectively decreases the number of alleles in a population, which results in reduced genetic variation. C happens if the bottleneck leaves behind more harmful alleles than "good" ones...but whether that happens or not is a matter of chance. In other words, not ALL bottlenecked populations are doomed to suffer from harmful alleles...but in all cases, genetic variation definitely decreases.