Which of the Following Is an Example of Natural Selection

Which of the following is an example of natural selection.

A) Rabbits run faster when they're chased by wolves than by foxes.
B) Deer learn to avoid the section of forest open for hunting.
C) As the climate warms over time, the fur coats on a population of black bears get thinner.
D) Turtles swim over whenever people come near a pond because they've adapted to being fed.
E) As the climate cools during the winter, birds eat more to maintain their temperature and energy level.