$R-CONH_2 \xrightarrow[{(2)H_3O^{+}}]{{(1)LiAlH_4}} P$ (Major),$P$ should be:

Choose the correct colour of the product for the following reaction.

Given below are two statements :
Statement $I$: Aniline reacts with conc. $H_2SO_4$ followed by heating at $453-473 \ K$ to give $p$-aminobenzene sulphonic acid (sulphanilic acid). This compound contains both nitrogen and sulphur,and thus it gives a blood red colour in the 'Lassaigne's test' due to the formation of ferric thiocyanate,$[Fe(SCN)]^{2+}$.
Statement $II$: In Friedel-Craft's alkylation and acylation reactions,aniline forms a salt with the $AlCl_3$ catalyst. Due to this,the nitrogen atom of aniline acquires a positive charge and acts as a deactivating group,preventing further reaction.
In the light of the above statements,choose the correct answer from the options given below :

The compound $A$ with the following sequence of reactions gives benzoic acid.
$A$ $\xrightarrow{NaNO_2/HCl} B$ $\xrightarrow{KCN} C$ $\xrightarrow{H_3O^{+}} \text{benzoic acid}$
The compound $A$ is:

Give uses of amine compounds as medicines.

For the transformation shown below,the reagent used is: