Give the structures of A, B and C in the following reactions : (a) CH_(3)-COOH overset(NH_(3)//Delta)(to) A overset(Br_(2)//KOH(aq))(to) B overset(CHCl_(3)+alc.KOH)(to) C (b) C_(6)H_(5)N_(2)^(+)BF_(4)^(-) underset(Delta)overset(NaNO_(2)//Cu)(to) A overset(Fe//HCl)(to) B overset(CH_(3)COCl//"pyridine")(to) C (c) C_(6)H_(5)CONH_(2) overset(Br_(2)//aq.KOH)(to) A underset(0-5""^(@)C)overset(NaNO_(2)+HCl)(to) B overset(KI)(to) C (d) CH_(3)-Cl overset(KCN)(to) A overset(LiAlH_(4))(to) B underset(Delta)overset(CHCl_(3)//Alc.KOH)(to) C (e) C_(6)H_(5)COO^(-)NH_(4)^(+) overset(Delta)(to) A overset(Br_(2)//KOH)(to) B underset("Pyridine")overset(CH_(3)COCl)(to) C (f) C_(6)H_(5)N_(2)^(+)BF_(4)^(-) underset(Delta)overset(NaNO_(2)//Cu)(to) A overset(Sn//HCl)(to) B overset(CHCl_(3)+alc.KOH)(to) C (g) ArNH_(2) underset(0-5""^(@)C)overset(NaNO_(2)//HCl)(to) A overset(CuCN)(to) B