Answer: The correct answer is "The particles of the medium vibrate up and down".
Step-by-step explanation:
Transverse wave is a wave in which the particles of the medium vibrate perpendicular to the direction of the wave.
For example, light wave. Transverse wave does not need any medium to travel.
In the given problem, a transverse wave is traveling from right to left. The direction of the particles of the medium vibrates up and down.