Here's a problem to solve: In December, one side of Earth will receive less energy from the Sun than the other side. Which statement best explains this fact?

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

- A: Earth rotates on its axis.
 
- B: Earth is tilted on its axis.
 
- C: Sunlight traveling to Earth reflects off the Moon.
 
- D: Sunlight traveling to Earth is blocked by Moon.
 