When the frequency of external exciting force is equal to the natural frequency of the vibration of
the system
A. The amplitude of vibration is zero
B. The amplitude of vibration is significantly small
C. The amplitude of vibration is very large
D. The amplitude does not change
the system
A. The amplitude of vibration is zero
B. The amplitude of vibration is significantly small
C. The amplitude of vibration is very large
D. The amplitude does not change