Step 1: Overview:
This question tests your knowledge of four named reactions in aromatic organic chemistry.
Step 2: Reaction Breakdown:
(A) Benzene diazonium chloride (from aniline, NaNO\(_2\)/HCl) reacts with Cu/HCl to form chlorobenzene. This is the Gatterman reaction. Therefore, (A) matches (III).
(B) A similar reaction to (A), but using cuprous salt (Cu\(_2\)Cl\(_2\)/HCl). This converts a diazonium salt to a halobenzene; it is the Sandmeyer reaction. So, (B) matches (II).
(C) Conversion of an amide (benzamide) to a primary amine (aniline) with fewer carbons, using bromine and sodium hydroxide (Br\(_2\)/NaOH). This is the Hofmann Bromamide degradation reaction. So, (C) matches (IV).
(D) Oxidation of a methyl group on an aromatic ring (toluene) to an aldehyde (benzaldehyde) using chromyl chloride (CrO\(_2\)Cl\(_2\)) in a non-polar solvent (CS\(_2\)). This is the Etard reaction. Hence, (D) matches (I).
Step 3: Answer:
The correct matching is: (A)-(III), (B)-(II), (C)-(IV), (D)-(I). This corresponds to option (1).