In the reaction $C_6H_6 + CO + HCl \xrightarrow{A} C_6H_5CHO + HCl$,what is $A$?

The reaction is given as follows:
$Ph-CO-N(CH_3)(OCH_3) + 2CH_3MgBr \xrightarrow{H_3O^+} (P)$
Product $(P)$ is:

$CH_3CH_2C \equiv N \xrightarrow{X} CH_3CH_2CHO$. The compound $X$ is:

Identify the product $Y$ in the following series of reactions.
$4-$Nitrotoluene $\xrightarrow[(CH_3CO)_2O / CrO_3]{273-278 \ K} X$ $\xrightarrow{H_3O^{+} / \Delta} Y$

The major products $P$ and $Q$ in the following reactions are:
$C_6H_5-CH=NOH$ $\xrightarrow{(i) (CH_3CO)_2O} P$ $\xrightarrow{(i) CH_3MgI, (ii) H_3O^+} Q$

Which of the following reactions is an example of Rosenmund reduction?