Here's a problem to solve: Which statement best explains why summer days are warmer than winter days in Arkansas?

Among the 4 following options, which is the correct answer?

- A: The Sun is closer to Earth in the summer than in the winter.
 
- B: The Sun has more sunspots in the summer than in the winter.
 
- C: Earth's western hemisphere is tilted toward the Sun during the summer.
 
- D: Earth's northern hemisphere is tilted toward the Sun during the summer.
 