Answer:
C.
Step-by-step explanation:
A compact fluorescent light bulb (CFL) contains a small quantity of mercury vapor. Mercury is used in CFLs to create ultraviolet light when electricity is applied to the bulb's electrodes. This ultraviolet light then interacts with phosphor coatings on the inside of the bulb, producing visible light. However, it's important to handle and dispose of CFLs properly because the release of mercury vapor can occur if a bulb is broken, and mercury is toxic to humans and the environment.