Identify the likely functional groups and their reduction reagents

From the table, only item $(C)$ is clearly visible as a nitrile: $(C) ext{: } R-C\equiv N$ Its reduction to a primary amine is classically done by: $R-C\equiv N \xrightarrow{\mathrm{LiAlH_4},\,H_2O} R-CH_2-NH_2$ So, $(C) \to (III)$

Use option elimination based on $(C)$

Check the options:

• A: $(C)-(III)$
• B: $(C)-(II)$
• C: $(C)-(IV)$
• D: $(C)-(III)$

Since nitriles are most appropriately reduced by $\mathrm{LiAlH_4}/H_2O$, only A and D remain possible.

Match the remaining standard transformations

Typical nitrogen-compound conversions to amines are:

• Nitro compounds are reduced by: $\mathrm{R-NO_2} \xrightarrow{\mathrm{Sn/HCl}} \mathrm{R-NH_2}$ So such a compound must match (IV).

• Amides are reduced by catalytic hydrogenation less commonly in JEE matching, while nitriles and some unsaturated nitrogen compounds are often associated with $\mathrm{H_2/Ni}$; however here nitrile is already best assigned to (III).

• Amides / related derivatives on alkaline hydrolysis with aqueous $\mathrm{NaOH}$ can give ammonia/amines in the corresponding listed transformation, so one of the remaining entries should match (I).

Compare options A and D

• Option A: $(A)-(II), (B)-(IV), (C)-(III), (D)-(I)$
• Option D: $(A)-(II), (B)-(I), (C)-(III), (D)-(IV)$

Since reduction by $\mathrm{Sn/HCl}$ is characteristically for a nitro compound, the entry corresponding to nitro compound should be paired with (IV). In the standard version of this question, that corresponds to (B), not (D).

Therefore, $(B) \to (IV),\quad (C) \to (III),\quad (D) \to (I),\quad (A) \to (II)$

Final matching

$(A)-(II),\ (B)-(IV),\ (C)-(III),\ (D)-(I)$

This is Option A.

Comparison with stored answer

Stored correct answer: B

My derived answer: A

These do not match.

Why stored answer B appears incorrect

In option B, the nitrile $(C)$ is matched with $\mathrm{H_2/Ni}$: $R-C\equiv N \to (II)$ While catalytic hydrogenation can reduce nitriles under suitable conditions, in standard JEE reagent-matching problems the most direct and unambiguous textbook reagent is: $\mathrm{LiAlH_4}, H_2O$ Hence $(C)-(III)$ is the expected match, making A the correct option.