Complete the following reactions
a. `underset((A))(PhNH_(2)) overset(HNO_(2))underset(0.5^(@)C)rarr (B) underset(DH_(2)PO_(2))rarr(C)`
b.
c. `underset((A))(PhCH)=O + underset((B))(HCN) rarr (C) overset(LAH)rarr D`
d. `underset((A))(PhCH=O) +underset((B))(MeNO_(2)) overset(Theta)overset(OH)rarr overset(Fe,FeSO_(4))underset(H^(o+))rarrD`
e.