Seasonal changes in snake activity are due to the fact that the snake

A)is less active in winter because the food supply is decreased.
B)is less active in winter because it does not need to avoid predators.
C)is more active in summer because that is the period for mating.
D)is more active in summer because it can gain body heat by conduction.
E)is more active in summer as a result of being disturbed by other animals.