14. The equation of motion of a particle of mass m oscillating along the x-axis under a driving force of amplitude F is m d2x/dt2= -kx – b 4x + F cos(wt). I The first term on the right represents the restoring force.
II The second term on the right represents the damping force.
III The resonance frequency for the system is w.
A) I, II, and III
B) III only
C) I and III only
D) I and II only