The major products obtained from the reactions in List-II are the reactants for the named reactions mentioned in List-I. Match each entry in List-I with the appropriate entry in List-II and choose the correct option. 
P → 5; Q → 4; R → 2; S → 1
(P) Stephen reaction:
Stephen reaction reduces nitriles (RCN) to aldehydes. The precursor is usually benzonitrile, which is derived from benzoic acid.
\[ \Rightarrow P \rightarrow \boxed{2} \quad \text{(Benzoic acid)} \] (Q) Sandmeyer reaction:
Used to substitute an amino group on an aromatic ring (from aniline) via diazotization. Requires a nitro compound as a precursor.
\[ \Rightarrow Q \rightarrow \boxed{3} \quad \text{(Nitrobenzene)} \] (R) Hoffmann bromamide degradation reaction:
Converts amides to amines with one fewer carbon. The amine product is Toluene.
\[ \Rightarrow R \rightarrow \boxed{4} \quad \text{(Toluene)} \] (S) Cannizzaro reaction:
Occurs with aldehydes having no alpha-H (like benzaldehyde), which can be derived from oxidation of toluene.
\[ \Rightarrow S \rightarrow \boxed{1} \quad \text{(Toluene)} \]
Final Answer: \( \boxed{\text{B}} \)
