An organic compound $[A]$ $(C_4H_{11}N)$ shows optical activity and gives $N_2$ gas on treatment with $HNO_2$. The compound $[A]$ reacts with $PhSO_2Cl$ producing a compound which is soluble in $KOH$. The structure of $A$ is:

The reduction of benzenediazonium chloride to phenylhydrazine can be accomplished by:

Consider the following sequence of reactions: $C_2H_5-Br$ $\xrightarrow{AgCN} A$ $\xrightarrow{H_2/Ni} B$. Product $B$ is:

Identify the correct statements:
$(A)$ Primary amines do not give diazonium salts when treated with $NaNO_2$ in acidic conditions.
$(B)$ Aliphatic and aromatic primary amines on heating with $CHCl_3$ and ethanolic $KOH$ form carbylamines.
$(C)$ Secondary and tertiary amines also give the carbylamine test.
$(D)$ Benzenesulfonyl chloride is known as Hinsberg's reagent.
$(E)$ Tertiary amines react with benzenesulfonyl chloride very easily.
Choose the correct answer from the options given below:

Aniline reacts with mixed acid (conc. $HNO_3$ and conc. $H_2SO_4$) at $288 \ K$ to give $P$ $(51 \%)$,$Q$ $(47 \%)$ and $R$ $(2 \%)$. The major product$(s)$ of the following reaction sequence is (are):
$R$ $\xrightarrow[2) Br_2, CH_3CO_2H]{1) Ac_2O, \text{pyridine}}$ $\xrightarrow{3) H_3O^+}$ $\xrightarrow{4) NaNO_2, HCl / 273-278 \ K}$ $\xrightarrow{5) EtOH, \Delta}$ $\xrightarrow{6) Sn/HCl}$ $\xrightarrow{7) Br_2/H_2O \text{ (excess)}} \text{Major Product}$

What are $X$ and $Y$ in the following reactions?