$CH \equiv CH$ $\xrightarrow{\text{Red Hot Fe tube}} A$ $\xrightarrow[\text{Dark}]{Cl_2 / FeCl_3} B$ $\xrightarrow[\text{Anhy. } AlCl_3]{CH_3 - Cl} C$ (Major)
Product '$C$' is

$Benzyne$ intermediate is not observed in :

The main product of the following reaction will be
$1$-fluoro-$2$-chloro-$4$-nitrobenzene + piperidine $\to$ Product

The catalyst used in Raschig's process is

The reaction of compound $P$ with $CH_3MgBr$ (excess) in $(C_2H_5)_2O$ followed by addition of $H_2O$ gives $Q$. The compound $Q$ on treatment with $H_2SO_4$ at $0^{\circ}C$ gives $R$. The reaction of $R$ with $CH_3COCl$ in the presence of anhydrous $AlCl_3$ in $CH_2Cl_2$ followed by treatment with $H_2O$ produces compound $S$ [$Et$ in compound $P$ is ethyl group].
$(1)$ The product $S$ is
$(2)$ The reactions,$Q$ to $R$ and $R$ to $S$,are

$A$. Dehydration and Friedel-Crafts acylation	$B$. Aromatic sulfonation and Friedel-Crafts acylation
$C$. Friedel-Crafts alkylation,dehydration and Friedel-Crafts acylation	$D$. Friedel-Crafts alkylation and Friedel-Crafts acylation

Given the answer question $(1)$ and $(2)$

In a reaction of $C_6H_5Y$,the major product obtained is the $60\%$ isomer. What is the group $Y$?