Iwill give brainliest if you answer

D. the warm air rises and moves back to the poles where it is cooled again.

Explanation:

One way to know that D is your answer is that hot air always rises.

That means 1 and 3 are not it.

It is not 2 because it will not just go back up into the atmosphere but go back towards the pole.

When it goes back towards the pole, that means D is your answer.

a. to encourage apoptosis

igneous rocks which formed by the crystallization of magma at the surface of the earth called extrusive rocks. they are characterized by fine-grained textures because the rapid cooling at or near the surface did not provide enough time for large crystals to grow.