Q38. Functional group present in sulphonic acids is :\\
(1) $- \mathrm { SO } _ { 4 } \mathrm { H }$\\
(2) $- \mathrm { SO } _ { 3 } \mathrm { H }$\\
(3) $- \underset { \text { II } } { \mathrm { S } } - \mathrm { OH }$\\
(4) $- \mathrm { SO } _ { 2 }$