(a) chlorofluorocarbon compounds
(b) carbon monoxide
(c) methane
(d) pesticides
Correct option – ( a )
Explanation for correct option – in the stratosphere chlorofluorocarbon compounds are broken down by the ultraviolet rays . Break down of chlorofluorocarbon compounds results in release of chlorine which interacts with ozone layer and is the reason for its depletion
Explanation for incorrect option – carbon monoxide , methane and pesticides do not contain chlorine which can react with ultra violet rays and cause depletion of ozone layer
Hence correct option is chlorofluorocarbon compounds .