What type of wave has disturbances that occur in the same direction as the wave's propagation?

The correct choice for the type of wave where disturbances occur in the same direction as the wave's propagation is the longitudinal wave. In this type of wave, particles of the medium move back and forth in the same direction as the wave travels. This means that when a longitudinal wave travels through a medium, the regions of compression and rarefaction are created as the particles are displaced along the same line as the wave itself.

In contrast, transverse waves have disturbances that occur perpendicular to the direction of wave propagation. In these waves, the oscillations move up and down while the wave travels horizontally, like a water wave or a wave on a string.

Electrical waves refer to electromagnetic radiation, which behaves differently from the mechanical waves described. Surface waves involve both transverse and longitudinal motion and typically occur at the interface between two different mediums, such as water waves on the surface of a body of water.

Thus, the defining characteristic of longitudinal waves—where the motion of the medium is in line with the direction of wave travel—makes it the correct answer in this context.