What causes temperatures in the summer to be higher than temperatures in the winter?
A.
The greenhouse effect, which raises temperatures on Earth, takes place during the summer months only.
B.
Volcanic activity is at its peak during the summer, resulting in elevated temperatures on Earth.
C.
More of the Sun's rays directly hit a particular region on Earth during the summer than during the winter.
D.
The Earth is closer in distance to the Sun during the summer than it is during the winter.