Which type of electric lighting utilizes gas discharge to produce light?

Fluorescent lighting is a type of electric lighting that utilizes gas discharge to produce light. In fluorescent lamps, an electric current passes through a gas, typically a low-pressure mixture of mercury vapor and inert gases like argon. This current excites the gas atoms, causing them to emit ultraviolet (UV) light. The interior of the lamp is coated with a phosphorescent material that converts the UV light into visible light, which is what we see when the lamp is illuminated.

This mechanism distinguishes fluorescent lights from other types. For instance, incandescent lighting generates light through the heating of a metal filament until it glows, rather than relying on gas discharge. Halogen lights are a type of incandescent lighting with a halogen gas that prolongs filament life but still relies on the filament heating method. Solid-state lighting, such as LED, involves semiconductor materials and does not employ gas discharge. Thus, fluorescent lighting is uniquely characterized by its use of gas discharge, making it the correct answer.