An organic compound “\( A \)” on treatment with benzene sulphonyl chloride gives compound \( B \), \( B \) is soluble in dil. \( \mathrm{NaOH} \) solution. Compound \( A \) is:
\( \mathrm{C_6H_5 - N-(CH_3)_2} \)
\( \mathrm{C_6H_5 - CH_2NHCH_3} \)
\( \mathrm{C_6H_5 - NHCH_2CH_3} \)