The distance between wave fronts of plane waves corresponds to ____ of a sound wave.

a. one wavelength
b. two amplitudes
c. one compression
d. two rarefactions

One wavelength. A wavelength is the distance that it takes for a wave pattern to repeat itself. A sound wave is a longitudinal wave (waves of pressure, alternating areas of high and low pressure). Still, you can measure the distance over which the pattern begins to repeat itself. Therefore, the distance between two wavefronts (on adjacent waves) would correspond to one wavelength.

Hope that helps! :)

wave fronts will be moving continuously.

Distance is between any two positions .

One position is the wave front at this instant.

Which is the other position of the wave front?.
======================================…

Meaningless question.