inertia of the moon location of earth's orbit speed of Earth's rotation Sun's gravitational pull
I gave my students this multiple choice question: What keeps the Earth in orbit around the Sun?

Only one answer is correct among these 4 choices:
- inertia of the moon
- location of earth's orbit
- speed of Earth's rotation
- Sun's gravitational pull

Could you tell me which one is correct?

Sun's gravitational pull