Answer:
Step-by-step explanation:
The label that identifies a rarefaction in a longitudinal wave is B.
In a longitudinal wave, such as a wave in a spring, a rarefaction is an area where the particles of the medium are farther apart than they are in the rest of the wave. This is in contrast to a compression, which is an area where the particles of the medium are closer together than they are in the rest of the wave.
In the given illustration, the area where the rings are further apart is labeled B, so B is the label that identifies a rarefaction. The area where the rings are closer together, labeled A, is a compression. The height of the spring, labeled C, does not correspond to a rarefaction or a compression, and the distance between adjacent areas where the rings are closer together, labeled D, is not related to the concept of rarefactions or compressions.