Answer:
LONGITUDINAL WAVE
Step-by-step explanation:
As we know that there are two type of propagation of wave
1) Transverse wave :
in transverse nature of waves the energy is propagated into the medium in perpendicular to the wave propagation.
So here in transverse waves the medium molecules will start oscillating in perpendicular direction
2) Longitudinal wave
Here in this type of wave the medium molecules will start oscillating in the direction of propagation of waves. So here the medium molecules will oscillate in the direction parallel to the wave propagation
so correct answer is
Longitudinal waves