A biologist conducting a long-term field study noticed there were two types of mice in a valley. one type of mouse had webbed toes, and one type of mouse lacked webbed toes. A dam was built in the valley turning the land into a wetland. As the years passed, all mice living in the valley were found to have webbed toes. No mice were found with non-webbed toes. ​​Which statement best explains the observed change in the mouse population?
A
Webbed toes in mice are controlled by the environment.
B
The mice grew webbing to move more efficiently in the new environment.
C
Webbed-toed mice survived better and reproduced more than mice without webbed toes.
D
The increased water levels in the valley increased the mutation rate in the mouse population.