Which relationship between Earth and the Sun explains the changing of the seasons during a year? A
During a year, the Sun expands to cause summer, and then contracts to cause winter.

B
The tilt of Earth's axis causes changes in the angle of the Sun's rays during a year.

C
As Earth travels closer to the Sun, summer occurs, and as it gets further away, winter occurs.

D
Yearly increases in solar activity cause summer, and decreases in solar activity cause winter.