Where does compression and rarefaction occur?
(A) Transverse Waves
(B) Non-Mechanical Waves
(C) Longitudinal Waves
(D) None

Hint Compression is formed when molecules are pressed or forced together. Compression is a region of high pressure. Rarefaction occurs where there is given extra space and is allowed to expand. It is a region where there is low pressure. They both occur in sound waves.

Complete step-by-step answer:
Sounds occur due to the series of vibrations. All sounds occur because of vibrations and energy. Waves make travel sounds. When a source which produces sound, vibrates, that transfers energy to the particles of the environment which causes them to vibrate. Those particles then bump into the ones next to them and this process continues. This process causes the sound particles to move back and forth but make energy waves to move outward in all directions from the source.
Waves consist of compressions and rarefactions.
Compression is a region in longitudinal waves which occurs in the high pressure and rarefaction is also a region in longitudinal waves which occurs where there is extra space or where particles are far away from each other. These both waves are of longitudinal waves of sound waves.
When a vibrating object goes forward in air as medium it pushes and compresses the air. This is the compression.
When a vibrating object goes back in air as medium it creates a region of low pressure. This is the rarefaction.

Therefore, option (C) is correct.

Note When a material is pushed it tries to oppose the applied force this is called the compression.
When a material is expanded outwards and its density becomes low it is called rarefaction. Rarefaction and compression are just opposite to each other.