Which of the following statements best describes polychromatic light?

The statement that describes polychromatic light as light composed of several wavelengths is accurate because polychromatic light consists of multiple colors or wavelengths within the visible spectrum and beyond. This means it can exhibit a range of colors, such as seen in sunlight or the output of certain LED sources, which blend together to produce white light.

In contrast, the other statements do not correctly characterize polychromatic light. Describing it as purely white does not capture the essence of its multiple wavelengths. The notion of polychromatic light being entirely absorbed misrepresents its nature, as absorption pertains to how materials interact with light, rather than the light itself. Similarly, the idea that polychromatic light travels faster than monochromatic light is incorrect; the speed of light is constant in a vacuum regardless of the number of wavelengths present. Thus, the best description of polychromatic light is indeed that it is composed of several wavelengths.