Which of the following is used in fire extinguishers?

bromofluorocarbons

The correct answer is option 2: bromofluorocarbons

Ozone depletion refers to the phenomenon of reductions in the amount of ozone in the stratosphere. The problem of ozone depletion is caused by high levels of chlorine and bromine compounds in the stratosphere. The origins of these compounds are chlorofluorocarbons (CFC), used as cooling substances in airconditioners and refrigerators, or as aerosol propellants, and bromofluorocarbons (halons), used in fire extinguishers.