Which of the following statements best describes the directional relationship between a system’s displacement from equilibrium and the net restoring force when the system executes simple harmonic motion?
(a) The restoring force is always directed opposite to the velocity of the system.
(b) The restoring force is always directed opposite to the displacement.
(c) The restoring force is always directed in the same direction as the displacement.
(d) The restoring force is perpendicular to the displacement at all times.