The correct option is B In the stratosphere, CFCs release chlorine free radicals (Cl) which reacts with O3 to give chlorine dioxide radicals.
Once CFCs are released in the atmosphere, they mix with the normal atmospheric gases and eventually reach the stratosphere. In stratosphere, they get broken down by powerful UV radiations, releasing chlorine free radical.
CF2Cl2(g)UV−−→⋅Cl(g)+⋅CF2Cl(g)
The chlorine radical then react with stratospheric ozone to form chlorine monoxide radicals and molecular oxygen instead of chlorine dioxide radical.
Cl⋅(g)+O3(g)→ClO⋅(g)+O2(g)
Hence, option (c) is not true about ozone.