Major end product of the following sequence of reaction is: $CH_3-CH_2-CH_2-CONH_2$ $\xrightarrow{Ca(OH)_2, Cl_2, \Delta} X$ $\xrightarrow{HNO_2} Z$

In a reaction of aniline,a coloured product $C$ was obtained as shown below:
$A$ $\xrightarrow{NaNO_2/HCl} B$ $\xrightarrow{N,N-dimethylaniline, \text{cold}} C$
The structure of $C$ would be:

Primary and secondary amines can be distinguished by $:-$

What are $X$ and $Y$ respectively in the following set of reactions?

Given below are two statements:
Statement-$I$ : Oxidation of $p$-nitrotoluene with acidic $KMnO_4$ gives an acid that is stronger than benzoic acid.
Statement-$II$ : Reduction of $p$-nitrotoluene with $Sn/HCl$ followed by neutralization gives an amine that is more basic than aniline.
In light of the above statements, choose the most appropriate answer from the options given below.

Aniline on treatment with $NaNO_2 / HCl$ at about $0^\circ C$ gives a compound $A$, which on further treatment with $CuCN / KCN$ gives a compound $B$, which when reacts with $H_2 / Ni$ gives a compound $C$. The compound $C$ on reaction with $HNO_2$ gives a compound $D$. The structure of $D$ is: