Which among the following compounds is treated with benzonitrile in dry ether followed by acid hydrolysis to obtain benzophenone?

Identify the final product $A$ in the given reaction sequence.

Explain the method of preparation of aldehydes and ketones from hydrocarbon (alkene and alkyne) compounds with suitable examples.

Consider the following reactions:
$C_2H_2 + H_2O \xrightarrow[333 \ K]{Hg^{2+} / H^{+}} [X] \stackrel{\text{Isomerisation}}{\rightleftharpoons} Y$
$Y$ cannot be obtained from which of the following reactions?

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

Among the following reagents,which one can convert an ester into an aldehyde?