Which among the following is the strongest base?

In the following sequence of reactions,what is $D$?
$Toluene$ $\xrightarrow{[O]} A$ $\xrightarrow{SOCl_2} B$ $\xrightarrow{NaN_3} C$ $\xrightarrow{Heat} D$

Product $(B)$ of this reaction is

The product of the above reaction is:

Identify $X$ and $Y$ in the following reactions:

When a concentrated solution of sulphanilic acid and $1-$naphthylamine is treated with nitrous acid $(273 \ K)$ and acidified with acetic acid,the mass $(g)$ of $0.1 \ mole$ of product formed is : (Given molar mass in $g \ mol^{-1} H: 1, C: 12, N: 14, O: 16, S: 32$)