Choose the incorrect statement.

The correct answer is Option (4) → Catalytic ozone distruction in stratosphere does not occur over Arctic (North Pole)

This statement is incorrect. Catalytic ozone loss does occur over the Arctic as well; in cold winters, polar stratospheric clouds form there too and substantial Arctic ozone depletion has been recorded, notably in 1997, 2011 and 2020. It is only milder and less regular than the Antarctic ozone hole because the northern polar vortex is weaker and warmer.

The other statements are correct: HCFCs release chlorine that destroys ozone catalytically (though far less than CFCs), ozone depletion potential is expressed relative to CFC-11 taken as 1.0, and the total column ozone of about 300 Dobson Units equals roughly 3 mm of pure ozone at standard temperature and pressure.