In the above chemical reaction, intermediate $"X"$ and reagent/condition $"A"$ are
(image) $+ NaNO_2+HCl \rightarrow $ product
${C_6}{H_5}N{H_2}\mathop {\xrightarrow{{NaN{O_2}/HCl}}}\limits_{0 - 5\,^o C} X\mathop {\xrightarrow{{HN{O_2}}}}\limits_{C{H_2}O} Y + {N_2} + HCl$
$X$ and $Y$ are respectively

$(a)$ $N,N-$ Dimethylaniline
$(b)$ $2,4 -$ Dimethylaniline
$(c)$ $N -$ methy $l-o-$ methylaniline
$(d)$ $p -$ Methylbenzylamine
