Toluene is oxidised by hot alkaline KMnO4 (then acidified) to A. A is treated with SOCl2, then excess NH3 to give B. B is warmed with Br2/KOH to give…

Step by step: toluene $\to$ benzoic acid (A) $\to$ benzoyl chloride $\to$ benzamide (B) $\to$ aniline (C, Hofmann bromamide degradation, one carbon is lost as carbonate) $\to$ benzenediazonium chloride (D) $\to$ azo coupling with phenol at the position para to $\mathrm{OH}$ gives $E=$ 4-hydroxyazobenzene, $\mathrm{HO{-}C_6H_4{-}N{=}N{-}C_6H_5}$ (SMILES $\mathrm{Oc1ccc(cc1)N{=}Nc1ccccc1}$). Count the chemically distinct carbons. The unsubstituted phenyl ring has a local mirror plane through C-1 and C-4 (given free rotation), so it shows 4 signals: ipso, ortho (2 equivalent), meta (2 equivalent) and para. The para-disubstituted ring has two different substituents but also a mirror plane, so it gives 4 signals: C bearing $\mathrm{OH}$, C bearing $\mathrm{N{=}N}$, and two pairs of equivalent CH carbons. The total is $4+4=8$.