Identify the product of the following reaction.

The following reactions are examples for $\underline{\left(\mathrm{i}\right)}$ and $\underline{\left(\mathrm{ii}\right)}.$

I 

II 

The major product of the following reaction is:

${\mathrm{CH}}_2=\mathrm{CHBr}\underset{\mathrm{Red} \mathrm{hot} \mathrm{iron} \mathrm{tube}, 873 \mathrm{K}}{\overset{{\mathrm{NaNH}}_2}{\to }}\mathrm{P}$

Identify the product of the following reaction.