Which among the following represent reagent 'A'?

Consider the following reaction sequence:

The product 'B' is :

Given below are two statements: one is labelled as Assertion $$\mathbf{A}$$ and the other is labelled as Reason $$\mathbf{R}$$

Assertion A : Aniline on nitration yields ortho, meta & para nitro derivatives of aniline.

Reason $$\mathrm{R}$$ : Nitrating mixture is a strong acidic mixture.

In the light of the above statements, choose the correct answer from the options given below

An organic compound $$'\mathrm{A}'$$ contains nitrogen and chlorine. It dissolves readily in water to give a solution that turns litmus red. Titration of compound $$'\mathrm{A}'$$ with standard base indicates that the molecular weight of $$'\mathrm{A}'$$ is $$131 \pm 2$$. When a sample of $$'\mathrm{A}'$$ is treated with aq. $$\mathrm{NaOH}$$, a liquid separates which contains $$\mathrm{N}$$ but not $$\mathrm{Cl}$$. Treatment of the obtained liquid with nitrous acid followed by phenol gives orange precipitate. The compound $$'\mathrm{A}'$$ is :