The correct option is A no change
The speed of the sound is no way affect by the wavelength of the sound wave as it affects the frequency or pitch of the sound. The speed of the sound is affected mainly by the external factors like the properties of the medium, temperature, etc.
Wavelength is determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings and is a characteristic of both, traveling waves and standing waves, as well as other spatial wave patterns.