What is the cause behind "Ozone depletion"?

Decreased bromine and chlorine compounds Increase in the level of CFC's Increased usage of AC, refrigerators etc. Both 2 and 3

Both 2 and 3

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, and bromofluorocarbons (halons), used in fire extinguishers.