What would be the final product [$$\mathbf{X}$$] formed when p-Toluidine undergoes the following series of reactions?

$$\begin{aligned} & \text { P-Toluidine } \xrightarrow[\text { Pyridine }]{\left\{\mathrm{CH}_2, \mathrm{CO}_2 \mathrm{O}\right.}[\mathrm{P}] \\ & {[\mathrm{P}] \xrightarrow{\mathrm{Br}_2 / \mathrm{CH}_3 \mathrm{COOH}}[\mathrm{O}]} \\ & {[\mathrm{Q}] \xrightarrow[\Delta]{\text { dilнG }}[\mathrm{R}]} \\ & {\mathrm{[R]} \xrightarrow[0^{\circ} \mathrm{C}]{\mathrm{Nan}_2 / \mathrm{HCl}}\mathrm{[S]}} \\ & {[\mathrm{S}] \xrightarrow{\mathrm{H}_2 \mathrm{PO}_2}[\mathrm{X}]} \\ \end{aligned}$$

Which of the following is highly basic?

Identify the product formed in the given reaction.

Which among the following will not liberate nitrogen on reaction with nitrous acid?