Compounds Containing Nitrogen

Identify the product ' B ' in the following sequence of reactions.

Ethanenitrile $\xrightarrow{\mathrm{SnCl}_2, \mathrm{HCl}} \mathrm{A} \xrightarrow{\mathrm{H}_3 \mathrm{O}^{+}} \mathrm{B}+\mathrm{NH}_4 \mathrm{Cl}$