Longitudinal waves
(a) usually occur in solids
(b) are formed by electromagnetic radiation
(c) have particle movement parallel to the direction of the energy
(d) have particle movement perpendicular to the direction of the energy

C

Explanation:

Since air molecules (the particles of the medium) are moving in a direction that is parallel to the direction that the wave moves, the sound wave is referred to as a longitudinal wave. The result of such longitudinal vibrations is the creation of compressions and rarefactions within the air.

Hope This Helped, -James