Here's a problem to solve: Giselle makes a model, using foam balls, to represent the events in a solar eclipse. To demonstrate this phenomenon best, the foam ball model should have which characteristic?

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

- A: the ability to revolve around the central ball
 
- B: a magnet in each ball
 
- C: a representation of oceans on each ball
 
- D: a source of thermal energy
 