`(A) overset(NH_(3))underset(Delta)rarr (B) underset(Br_(2)+KOH)rarr (C) (C_(6)H_(7)N)`
`(A)` is acid, (B) is amide, and (C) is amine.
`D.U.` in `(C) = ((2n_(C)+2)-(n_(H)-n_(N)))/(2)=(14-6)/(2)=4^(@)`
4 D.U. in (C) and `C:H ~~ 1:1` suggest that (C) contains benzene ring, therefore (C) us aniline and thus (A) is benzoic acid.