What are the two main types of waves?

The correct answer identifies the two primary categories of waves based on how they propagate through different mediums. Mechanical waves require a medium (like air, water, or solid matter) to travel, meaning they cannot exist in a vacuum. Examples of mechanical waves include sound waves and seismic waves. Electromagnetic waves, on the other hand, do not require a medium to propagate; they can travel through a vacuum, which is how light from the Sun reaches Earth. Common examples of electromagnetic waves are radio waves, microwaves, and visible light.

This classification is fundamental in understanding wave behavior and phenomena in various physical contexts, such as sound transmission and light propagation. The other options, while they feature different classifications or examples of waves, do not encompass the main categories based on medium requirements and propagation methods as clearly as mechanical and electromagnetic waves do.