(N/A) $(i)$ Methyl benzoate: Benzene $\xrightarrow{CH_3Cl, AlCl_3}$ Toluene $\xrightarrow{KMnO_4, OH^-}$ Benzoic acid $\xrightarrow{CH_3OH, H^+}$ Methyl benzoate.
$(ii)$ $m$-Nitrobenzoic acid: Benzene $\xrightarrow{CH_3Cl, AlCl_3}$ Toluene $\xrightarrow{conc. HNO_3, conc. H_2SO_4}$ $p/o$-Nitrotoluene (separate $m$-isomer) $\xrightarrow{KMnO_4, OH^-}$ $m$-Nitrobenzoic acid.
$(iii)$ $p$-Nitrobenzoic acid: Benzene $\xrightarrow{CH_3Cl, AlCl_3}$ Toluene $\xrightarrow{conc. HNO_3, conc. H_2SO_4}$ $p$-Nitrotoluene $\xrightarrow{KMnO_4, OH^-}$ $p$-Nitrobenzoic acid.
$(iv)$ Phenylacetic acid: Benzene $\xrightarrow{CH_3Cl, AlCl_3}$ Toluene $\xrightarrow{Cl_2, h\nu}$ Benzyl chloride $\xrightarrow{KCN}$ Benzyl cyanide $\xrightarrow{H_3O^+}$ Phenylacetic acid.
$(v)$ $p$-Nitrobenzaldehyde: Benzene $\xrightarrow{CH_3Cl, AlCl_3}$ Toluene $\xrightarrow{conc. HNO_3, conc. H_2SO_4}$ $p$-Nitrotoluene $\xrightarrow{CrO_2Cl_2, CS_2, H_3O^+}$ $p$-Nitrobenzaldehyde.