Answer:
C. Frequency
Step-by-step explanation:
As we know that the characteristics of sound is as following
1) Loudness : loudness of sound depends on the amplitude of sound so on increasing the loudness the amplitude will also increase.
2) Quality of sound : Quality of sound depends on the type of waveform. For different waveform the quality of sound is also different.
3) Pitch of sound : it depends on the frequency of the sound which means if the frequency of sound is more then its frequency will be more
So here correct answer will be
C). Frequency