Which type of wave sound is?
Both A and B
A wave which travels parallel to the direction of motion of particles is called as longitudinal wave.
A mechanical wave is the one which requires a material medium to propagate through.
Sound travels through compressions and expansions of air. The wave travels parallel to the direction of motion of the wave. Hence it is a longitudinal wave.
Sound requires a medium to propagate which implies that it is a mechanical wave.