What does the molecular formula $C_3H_9N$ represent?

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.

The incorrect statement regarding the reaction shown below is:

The major product $Z$ formed in the following sequence of reactions is:

Give the structures of $A$,$B$ and $C$ in the following reactions:
$(i)$ $CH_3CH_2I$ $\xrightarrow{NaCN} A$ $\xrightarrow[Partial\,hydrolysis]{OH^{-}} B$ $\xrightarrow{NaOH+Br_2} C$
$(ii)$ $C_6H_5N_2Cl$ $\xrightarrow{CuCN} A$ $\xrightarrow{H_2O/H^{+}} B$ $\xrightarrow[\Delta]{NH_3} C$
$(iii)$ $CH_3CH_2Br$ $\xrightarrow{KCN} A$ $\xrightarrow{LiAlH_4} B$ $\xrightarrow[0\ ^oC]{HNO_2} C$
$(iv)$ $C_6H_5NO_2$ $\xrightarrow{Fe/HCl} A$ $\xrightarrow[273\ K]{NaNO_2+HCl} B$ $\xrightarrow[\Delta]{H_2O/H^{+}} C$
$(v)$ $CH_3COOH$ $\xrightarrow[\Delta]{NH_3} A$ $\xrightarrow{NaOBr} B$ $\xrightarrow{NaNO_2/HCl} C$
$(vi)$ $C_6H_5NO_2$ $\xrightarrow{Fe/HCl} A$ $\xrightarrow[273\ K]{HNO_2} B$ $\xrightarrow{C_6H_5OH} C$

Match each of the compounds in Column $I$ with its characteristic reaction$(s)$ in Column $II$.

Column $I$	Column $II$
$A$. $CH_3CH_2CH_2CN$	$p$. Reduction with $Pd-C/H_2$
$B$. $CH_3CH_2OCOCH_3$	$q$. Reduction with $SnCl_2/HCl$
$C$. $CH_3-CH=CH-CH_2OH$	$r$. Development of foul smell on treatment with chloroform and alcoholic $KOH$
$D$. $CH_3CH_2CH_2CH_2NH_2$	$s$. Reduction with diisobutylaluminium hydride $(DIBAL-H)$
	$t$. Alkaline hydrolysis