How does aniline react with sodium nitrite/$\mathrm{HCl}$?

In the following reaction, X is 

$\mathrm{X}\stackrel{\mathrm{Bromination}}{\to }\mathrm{Y}\stackrel{{\mathrm{NaNO}}_2/\mathrm{HCl}}{\to }\mathrm{Z}\underset{{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}}{\overset{\mathrm{Boiling}}{\to }}\mathrm{Tribromobenzene}$

Reduction of nitrobenzene by which of the following reagents gives aniline?

${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{NO}}_2\stackrel{\mathrm{Sn}/\mathrm{HCl}}{\to }{\mathrm{C}}_6{\mathrm{H}}_5\mathrm{X}$

In the above reaction $\left(\mathrm{X}\right)$ is