Here's a problem to solve: A large, solid spherical body in the solar system is classified as a moon. Which characteristic of the body gives it this classification?

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

- A: It rotates on its axis.
 
- B: It lacks liquid water.
 
- C: It orbits a nearby planet.
 
- D: It reflects light from a star.
 