Which description best defines specular reflection?

• A. Diffraction around an obstacle
• B. Absorption in tissue
• C. Specular Reflection from a Smooth, Large Interface
• D. Scattering from a rough surface

Answer: (C)

Specular reflection occurs when light encounters a smooth, large interface and reflects in a well-defined direction, with the angle of incidence equal to the angle of reflection. This coherent, mirror-like return is why polished mirrors and calm water can clearly show an image. The description is the best fit because it specifies a smooth, large interface, which lets the reflected waves stay organized rather than scatter. By contrast, diffraction around an obstacle involves bending and interference of waves at edges, absorption in tissue concerns energy loss rather than reflection, and scattering from a rough surface distributes light in many directions, producing no sharp reflection.