Answer: The correct answer is light wave.
Step-by-step explanation:
Longitudinal wave requires medium to travel. It can travel in solid, liquid and gas. For example, sound wave. Sound wave travels faster in the solid than in liquid. It travels slowest in gaseous state.
Ultrasonic wave is a sound wave having frequency more than 20,000 Hz. It is inaudible to human being.
Transverse wave does not require any medium to travel. It can travel through vacuum.
For example, light wave.
Therefore, light wave requires no medium.