How does the mechanical energy of a rock change as it falls from a mountain? A The mechanical energy remains the same because kinetic energy is changed into potential energy.

B The mechanical energy remains the same because potential energy is changed into kinetic energy.

C The mechanical energy increases because the kinetic energy is changed into speed, while the potential energy remains the same.

DThe mechanical energy increases because the potential energy is changed into acceleration, while the kinetic energy remains the same.​