It becomes warmer and forms clouds. It becomes cooler and forms clouds. Its temperature remains the same. Its temperature varies greatly.
I gave my students this multiple choice question: What happens to a moist air mass as it moves upward in the atmosphere?

Only one answer is correct among these 4 choices:
- It becomes warmer and forms clouds.
- It becomes cooler and forms clouds.
- Its temperature remains the same.
- Its temperature varies greatly.

Could you tell me which one is correct?

It becomes cooler and forms clouds.