An organic compound "A" on treatment with benzene sulphonyl chloride gives compound B. B is soluble in dil. NaOH solution. Compound A is :

In simple words the compound must be primary amine since it reacts with Hiensberg reagent as well as base added and forms a soluble salt, secondary amine only react with Hiensberg reagent not with base, and tertiary amines react with with none.