Answer: The correct answers are parallel and perpendicular.
Explanation:
Wave is a disturbance which carries energy from one particle to another.
There are two types of the mechanical waves: Longitudinal wave and transverse wave.
In the longitudinal wave, the particle vibrates parallel to the direction of the motion of the wave. For example, sound wave.
In the transverse wave, the particle vibrates perpendicular to the direction of the motion of the wave. For example, light wave.
Therefore, A longitudinal wave is a type of wave that transfers energy parallel to the direction of wave motion.
A transverse wave, on the other hand, is a type of wave that transfers energy perpendicular to the direction of wave motion.
