Answer:
I believe it is C: The angle of incoming sunlight varies at different places.
Explanation:
The sun is a large star full of heat, when the sun is down and the moon is up, then it get i little bit less warmer. The earth is still warm, just less warmer when its not tilted at your position.
(Credits to "FactOTheDay" for helping the answer for this answer).
(also i don't know if you are asking this as a question from edmentum. I'm just putting out the answer for the edmentum users.)
