The Moon has a thinner atmosphere than Earth. The Moon is too large to move away from Earth. The Moon is attracted by the gravity of Earth. The Moon has a smaller gravitational force than Earth.
I gave my students this multiple choice question: Which is the best explanation of why the Moon revolves around Earth?

Only one answer is correct among these 4 choices:
- The Moon has a thinner atmosphere than Earth.
- The Moon is too large to move away from Earth.
- The Moon is attracted by the gravity of Earth.
- The Moon has a smaller gravitational force than Earth.

Could you tell me which one is correct?

The Moon is attracted by the gravity of Earth.