Gravitational Potential Energy: Is It Possible for a System to Have

Gravitational potential energy: Is it possible for a system to have negative potential energy?

A) Yes, as long as the kinetic energy is positive.
B) Yes, as long as the total energy is positive.
C) Yes, since the choice of the zero of potential energy is arbitrary.
D) No, because the kinetic energy of a system must equal its potential energy.
E) No, because this would have no physical meaning.