Answer: A crest in a transverse wave corresponds to a Compression in a longitudinal wave.
Step-by-step explanation:
A transverse wave has crests and troughs. Crest and trough are the points on the wave to which maximum displacement of medium particles in upward and downward direction occurs respectively. The medium particles vibrate perpendicular to the direction of propagation of wave.
A longitudinal wave has compression and rarefaction. The medium particles vibrate parallel to the direction of propagation of wave. A compression is high density region and rarefaction is a low density region.
A crest is the point on the transverse wave to which the medium particle rises maximum. Correspondingly, in a longitudinal wave, the medium particles come closer to each other and form a denser region. This is known as compression.