Select the Scenario in Which a Mutation May Become Fixed

Select the scenario in which a mutation may become fixed in a population.

A) A mutation causing light skin shows up in a population of people living near the equator in South America.
B) A mutation for a stubby tail occurs in a population of Eastern gray squirrels,which normally have long,bushy tails.
C) Several bacteria in a population resistant to the antibiotic erythromycin show susceptibility to erythromycin because of a recent mutation.
D) A mutation occurs in a population of brown toads,causing green stripes that allow for better camouflaging in its habitat.
E) In a population of people whose main food source is the milk of their livestock,a mutation for lactose intolerance appears.