Sea turtles, dolphins, and whales all live in the ocean. How do the respiratory systems of these three types of animals limit their behavior?

A. They must eat very small pieces of food, because larger pieces would clog their respiratory tracts.
B. They must live only in warm waters, which their lungs require.
C. They must live in waters where the oxygen content is relatively high, which their gills require.
D. They must swim to the surface to breathe, because their lungs require air and not water.