Final answer:
A wave is a disturbance that transfers energy from one place to another. Mechanical waves require a medium to travel through, while light waves can travel through a vacuum. The correct answer is Medium.
Step-by-step explanation:
A wave is a disturbance that travels or propagates from the place where it was created, transferring energy from one place to another. Mechanical waves, such as sound waves and water waves, require a medium to travel through. Light waves, on the other hand, are not mechanical waves and can travel through a vacuum. Therefore, the correct answer to the question is B) Medium.