Three isomers $A$,$B$,and $C$ (molecular formula $C_8H_{11}N$) give the following results:
$A$ and $C$ $\xrightarrow{\text{Diazotization}}$ $P + Q$ $\xrightarrow[(ii) \text{ oxidation } (KMnO_4 + H^{+})]{(i) \text{ Hydrolysis}}$ $R$ (product of $A$) and $S$ (product of $C$)
Identify $A$,$B$,and $C$ from the given options.

• A
  $A$ = $o$-ethylaniline,$B$ = $m$-ethylaniline,$C$ = $p$-ethylaniline
• B
  $A$ = $o$-ethylaniline,$B$ = $N$-methylbenzylamine,$C$ = $p$-ethylaniline
• C
  $A$ = $p$-ethylaniline,$B$ = $N$-ethylaniline,$C$ = $o$-ethylaniline
• D
  $A$ = $m$-ethylaniline,$B$ = $N$-methylbenzylamine,$C$ = $o$-ethylaniline