- Ethyl bromide (A) undergoes an S\(_N\)2 reaction (bimolecular nucleophilic substitution) because it is a primary alkyl halide.
- Tertiary butyl bromide (B) undergoes an S\(_N\)1 reaction (unimolecular nucleophilic substitution) due to the formation of a stable carbocation.
- Acetone (C) reacts with nucleophiles via nucleophilic addition due to the presence of a carbonyl group.
- Benzene (D) is reactive towards electrophilic substitution due to its aromaticity.
Step 2: Conclusion.
Therefore, the correct matching is: \[\text{(A) (I), (B) (II), (C) (IV), (D) (III)}\]
Final Answer:\[\boxed{\text{(A) (I), (B) (II), (C) (IV), (D) (III)}}\]