orbits of the planets around the Sun rotation of a planet on its axis tilt of Earth's axis phases of the Moon
I gave my students this multiple choice question: Gravity is responsible for the ___.

Only one answer is correct among these 4 choices:
- orbits of the planets around the Sun
- rotation of a planet on its axis
- tilt of Earth's axis
- phases of the Moon

Could you tell me which one is correct?

orbits of the planets around the Sun