Saponification (basic hydrolysis) of $C_6H_5-CO-^{18}OCH_3$ will yield. [$^{18}O$ = mass $-18$ isotope of oxygen]

Calculate the value of $x + \text{molecular mass of } (C)$,where $x$ is the number of moles of $PhMgBr$ consumed in reaction $(a)$ and $(C)$ is the gas evolved in reaction $(b)$.
$(a)$ $3\text{-hydroxy-5-formylbenzoyl chloride} + x \ PhMgBr \xrightarrow{\text{excess}} (A)$
$(b)$ $2,5\text{-dioxocyclohexanecarboxylic acid} \xrightarrow{\Delta} (B) + (C) \uparrow$

The following transformation can be carried out in three steps. The reagents required for these three steps in their correct order are:

Match the following.

List-$I$ (Substance)	List-$II$ (Use)
$(A)$ Methanoic acid	$(i)$ Textile
$(B)$ Ethanoic acid	$(iv)$ Vinegar
$(C)$ Hexanedioic acid	$(ii)$ Polymer
$(D)$ Sodium benzoate	$(iii)$ Food preservative

What will be $X$ and $Y$ in the following reactions?

Match the reactions given in Column-$I$ with their names in Column-$II$.

Column-$I$ (Reaction)	Column-$II$ (Name)
$A$. $RCH_2COOH \rightarrow[H_2O]{X_2/P} RCH(X)COOH$	$i$. Decarboxylation
$B$. $RCOONa \rightarrow[NaOH, CaO, \Delta]{\text{soda lime}} RH$	$ii$. Grignard reaction
$C$. $RCOOH + R'OH \leftrightarrow{H^{+}} RCOOR' + H_2O$	$iii$. Hell-Volhard-Zelinsky reaction
$D$. $RMgX + R'CHO \rightarrow{H_3O^{+}} RCH(OH)R'$	$iv$. Esterification