The end product of the reaction $C_2H_5NH_2$ $\xrightarrow{HNO_2} A$ $\xrightarrow{PCl_5} B$ $\xrightarrow{KCN} C$ is

The final product $[B]$ is :

$A$ nauseating smell in the carbylamine test for primary amines is due to the formation of

The major products $A$ and $B$ formed in the following reaction sequence are :

Given below are two statements:
Statement $I$: Pure Aniline and other arylamines are usually colourless.
Statement $II$: Arylamines get coloured on storage due to atmospheric reduction.
In the light of the above statements,choose the most appropriate answer from the options given below:

When ethyl amine is heated with chloroform and alcoholic $KOH$,a compound with an offensive smell is obtained. This compound is