The main difference between a series and a parallel circuit is that
a. more components can be added to a parallel circuit.
b. the voltage source for a series circuit can be weaker.
c. in a series circuit there's only one path for current to flow.
d. a parallel circuit can handle components with higher resistances.

i think its

answer would be letter choice (a),   a ball resting on a shelf. would be another example of potential energy   >   stored energy > not moving.

a ball spinning on a finger   >   kinetic energy > moving energy

a ball rolling on the ground   >   kinetic energy   > moving energy

a   ball flying through the air   > kinetic energy   >   moving energy

hope that                                         : )