The formation of ozone hole in the Antarctic region has been a cause of concern. What could be the reason for the formation of this hole?[UPSC 2011 (CS-P)]

Presence of prominent tropospheric turbulence; and inflow of chlorofluorocarbons
Presence of prominent polar front and stratospheric clouds; and inflow of chlorofluorocarbons.
Absence of polar front and stratospheric clouds; and inflow of methane and chlorofluorocarbons.
Increased temperature at polar region due to global warming