Solution
✅ Correct Option: 2
The Montreal Protocol banned CFCs, carbon tetrachloride, trichloroethane and bromine compounds (halons). 'Carbon chloride' is not among the substances listed as banned in the passage.
Note: Option 2 reads 'carbon chloride' while the passage names 'carbon tetrachloride'; we treat these as distinct, making option 2 the substance not banned.