The correct answer is (c), sound wave. Sound waves are mechanical waves, which means they require a medium to travel through. Electromagnetic waves, on the other hand, are transverse waves that can travel through the vacuum of space.
Light waves, radio waves, and microwaves are all types of electromagnetic waves. They differ in their wavelength, which is the distance between two consecutive peaks of the wave. Light waves have the shortest wavelength, followed by radio waves, and then microwaves.
Sound waves are longitudinal waves, which means the particles of the medium vibrate in the same direction as the wave is traveling. Sound waves can travel through solids, liquids, and gases. The speed of sound depends on the medium through which it is traveling. Sound travels fastest in solids, followed by liquids, and then gases.
I hope this helps! Let me know if you have any other questions.