Over many generations darker for color becomes more common in a population of squirrels living in a shady area

The answer is letter b. adaptation. Adaptation occurs when living organisms adapt to their surroundings or environment over a long period of time. In this case, Dark Furred Squirrels were abundant, since squirrels adapted to the dark shady area they have lived and adapted into a dark furred one, which allowed it to be more common due to adaptation.

a

explanation:

many plants naturally reproduce this way, but it can also be induced artificially. horticulturalists have developed asexual propagation techniques that use vegetative plant parts to replicate plants. success rates and difficulty of propagation vary greatly. monocotyledons typically lack a vascular cambium and therefore are harder to propagate.