Earth rotates on its axis. Earth is tilted on its axis. Sunlight traveling to Earth reflects off the Moon. Sunlight traveling to Earth is blocked by Moon.
I gave my students this multiple choice question: In December, one side of Earth will receive less energy from the Sun than the other side. Which statement best explains this fact?

Only one answer is correct among these 4 choices:
- Earth rotates on its axis.
- Earth is tilted on its axis.
- Sunlight traveling to Earth reflects off the Moon.
- Sunlight traveling to Earth is blocked by Moon.

Could you tell me which one is correct?

Earth is tilted on its axis.