Answer:
Wavelength
Explanation:
Compression and rarefaction in a longitudinal wave correspond respectively, to the wavelength of a transverse wave.
Compression is the part of a wave where the density of particles are very close to each other while the rarefaction is the part of a wave where the particles are far apart from each other.These are the parts of longitudinal waves.
So, the correct option is (a) "wavelength".