Freons are chlorofluorocarbons, compounds containing carbon, chlorine and fluorine, of which dichlorodifluoromethane, CF2Cl2, known as Freon-12, is a classic example. They are stable, non-toxic and non-flammable, which made them ideal aerosol propellants and refrigerants, but their inertness lets them reach the stratosphere where ultraviolet light releases chlorine atoms that catalytically destroy ozone. The iodoform option is wrong because iodoform, CHI3, is a yellow antiseptic solid and is not a refrigerant or propellant. The carbon tetrachloride option is incorrect because, although it is a halogen compound, it was used as a solvent and fire extinguisher, not as an aerosol propellant, and it is not a chlorofluorocarbon. The DDT option is wrong because DDT is a chlorinated aromatic insecticide, unrelated to refrigeration. This matches the NCERT discussion of freons and ozone depletion. Sanity check: the only chlorofluorocarbon refrigerant listed is the freon, confirming the answer.