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

In the following sequence of reactions,the maximum number of atoms present in molecule $C$ in one plane is:
$A$ $\xrightarrow[Cu \text{ tube}]{\text{Red hot}} B$ $\xrightarrow[\text{Anhydrous } AlCl_3]{CH_3Cl (1 \text{ eq})} C$
($A$ is the lowest molecular weight alkyne)

During the mixed acid nitration of benzene,concentrated $HNO_3$ behaves like:

In the following set of aromatic compounds,the correct order of reactivity toward Friedel-Crafts alkylation is:
$(i)$ Nitrobenzene
(ii) Benzene
(iii) Methyl benzoate
(iv) Anisole

Identify the correct statement regarding the products $A$ and $B$ formed in the following reactions of benzene:
$1$. Benzene + $6Cl_2$ $\xrightarrow{AlCl_3 \text{ (excess)}}$ $A$
$2$. Benzene + $Cl_2$ (excess) $\xrightarrow{h\nu, 500 \ K}$ $B$

The product $(A)$ is: