Answer:
a) Transverse and longitudinal
Step-by-step explanation:
Depending on the medium in which the sound is traveling the wave can be longitudinal or transverse.
When traveling in fluids i.e., in liquids and gases the wave takes the form of a longitudinal wave. Longitudinal waves cause compression and rarefaction of the fluid.
When traveling in solids the wave takes the form of a transverse wave. Transverse waves leads to the formation of shear stresses in the solid.