Correct Option: D

In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. At least two of the flat surfaces must have an angle between them. The exact angles between the surfaces depend on the application. The traditional geometrical shape is that of a triangular prism with a triangular base and rectangular sides, and in colloquial use “prism” usually refers to this type. A prism can be used to break light up into its constituent spectral colours (the colours of the rainbow). Prisms can also be used to reflect light, or to split light into components with different polarizations. Prisms are sometimes used for the internal reflection at the surfaces rather than for dispersion.