Chlorination of sulfobenzoicacid
Yes, You are correct. ortho-Chlorobenzoic acid is the final answer, Actually G contains COOK group, which is then treated with HCl to turn it into COOH. In the last step, desulphonation takes place because that is what happens when you treat sulphobenzene compound with water at high temperatures.
Sulphonation is a reverse process and at high temperature desulphonation will happen.