The correct answer is A. Frequency.
Frequency is the number of waves that pass a given point in a given amount of time. It is measured in Hertz (Hz), which is the number of waves per second. The higher the frequency, the higher the pitch.
Intensity is the amount of energy in a sound wave. It is measured in decibels (dB). The higher the intensity, the louder the sound.
Velocity is the speed of a sound wave. It is measured in meters per second (m/s). The velocity of sound depends on the medium through which it is traveling. For example, sound travels faster through air than through water.
Amplitude is the maximum displacement of a sound wave from its equilibrium position. It is measured in meters. The higher the amplitude, the louder the sound.
In conclusion, the pitch of sound depends on its frequency. The higher the frequency, the higher the pitch.