the tilt of Earth on its axis the rate of rotation of Earth the effects of solar flare activity the relative distance between Earth and the Sun
I gave my students this multiple choice question: Seasons in Alaska are primarily caused by which factor as Earth revolves around the Sun?

Only one answer is correct among these 4 choices:
- the tilt of Earth on its axis
- the rate of rotation of Earth
- the effects of solar flare activity
- the relative distance between Earth and the Sun

Could you tell me which one is correct?

the tilt of Earth on its axis