What are the structures of $X$,$Y$,and $Z$ in the above given reaction sequence?

Identify the product $B$ in the following reaction:
$C_6H_5NH_2$ $\xrightarrow[0^\circ-5^\circ C]{NaNO_2/HCl} A$ $\xrightarrow{Ph-N(CH_3)_2} B$

$STATEMENT-1$: Aniline on reaction with $NaNO_2 / HCl$ at $0^{\circ} C$ followed by coupling with $\beta$-naphthol gives a dark blue coloured precipitate.
$STATEMENT-2$: The colour of the compound formed in the reaction of aniline with $NaNO_2 / HCl$ at $0^{\circ} C$ followed by coupling with $\beta$-naphthol is due to the extended conjugation.

Primary and secondary amines are distinguished by
$(i)$ Hinsberg test
$(ii)$ Carbyl amine test
$(iii)$ Hofmann mustard oil test
$(iv)$ $HNO_2$ test

Suppose the following reaction:
The product $D$ and $F$ are related as:

What are $X$ and $Y$ respectively in the following set of reactions?