Answer:
D. In both, vibrations occur in a parallel direction to the direction of the wave.
Step-by-step explanation:
It is not true that in both mechanical and electromagnetic waves, vibrations occur in parallel direction to the direction of the wave.
As with all waves, they are disturbances that transfers energy without moving the materials of the medium.
- Electromagnetic waves have only one way of propagation which is a vibration in both parallel and longitudinal direction.
- Mechanical waves can be propagated either in a parallel direction or longitudinal direction and not both.