Which lists important roles of coral reefs?

cleaning oil from oceans, protecting beaches, producing oxygen
producing oxygen, offering medical benefits to humans, supporting a variety of organisms
supporting a variety of organisms, cleaning oil from oceans, producing oxygen
offering medical benefits to humans, protecting beaches, supporting a variety of organisms

supporting a variety of organisms, cleaning oil from oceans, producing oxygen

Explanation:

While they do have some medical benefits, those are still being explored and its looking for important roles these seem more important.

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.