To identify compound X, we need to analyze the reaction sequence.$\\$1. The first reaction is the chlorination of toluene $($C$_6$H$_5$CH$_3)$ under light $(h\nu). \\$ This is a free radical substitution reaction.$\\$2. In the presence of $h\nu,$ chlorine radicals are generated, which substitute hydrogen atoms in the methyl group.$\\$ The first substitution forms benzyl chloride $($C$_6$H$_5$CH$_2$Cl$). \\$3. Further chlorination can occur, leading to the formation of benzylidene chloride $($C$_6$H$_5$CHCl$_2). \\$4. The second step involves hydrolysis of compound X at $373$ K.$\\$ Benzylidene chloride $($C$_6$H$_5$CHCl$_2)$ undergoes hydrolysis to form benzaldehyde $($C$_6$H$_5$CHO$). \\$Therefore, compound X is benzylidene chloride $($C$_6$H$_5$CHCl$_2). \\$This corresponds to Option 2.