The range of hearing of the human ear is 20 to 20,000 Hz, below or above the frequency of vibration of the sound, the human ear can not be heard, so A is wrong, D is correct.
Amplitude is the maximum distance that an object can deviate from its original position when vibrating, so B is wrong.
The number of times an object vibrates per second is called the frequency of vibration, so C is wrong.