Which statement best describes electromagnetic waves such as visible light?

• A. They require a material medium to propagate.
• B. They are a form of mechanical energy traveling in waves.
• C. They are energy that travels in waves through space.
• D. They cannot travel through a vacuum.

Answer: (C)

Electromagnetic waves are disturbances in electric and magnetic fields that carry energy and can propagate through space without a material medium. Visible light, like other EM waves, can travel from the Sun to Earth through the vacuum of space while delivering energy. This makes the description "energy that travels in waves through space" the best fit. The idea that they require a medium or that they are mechanical energy doesn’t apply, since EM waves do not need a substance to move and are not mechanical waves. They can also travel through a vacuum, unlike waves that must move through a material.