Which type of reflection does not maintain the original path of the incoming beam?

Diffuse reflection is characterized by scattering light in multiple directions, which results in a loss of the original path of the incoming beam. This occurs when light rays strike a rough or uneven surface, causing them to bounce off at various angles rather than following a single, predictable reflected path.

In contrast, specular reflection occurs on smooth surfaces, where incoming light is reflected at consistent angles, maintaining the direction of the beam. Refraction involves the bending of light as it passes through different media, altering its path but not reflecting it. Scattering refers to the random redirection of light in many directions due to particles in a medium, but it is a broader term that encompasses various phenomena.

Thus, among these methods of light interaction, diffuse reflection is the only type that does not keep the original trajectory of the beam.