Earth's tilt on its axis the Sun's tilt on its axis Earth spinning on its axis the Sun spinning on its axis
I gave my students this multiple choice question: The length of daylight changes as the seasons change during the year. What causes these changes in daylight?

Only one answer is correct among these 4 choices:
- Earth's tilt on its axis
- the Sun's tilt on its axis
- Earth spinning on its axis
- the Sun spinning on its axis

Could you tell me which one is correct?

Earth's tilt on its axis