If $(\pm)$ $2$-methylbutanoic acid is esterified by reaction with $(\pm)$ $2$-butanol,how many optically active compounds will be present in the final equilibrium reaction mixture?

$CH_3-CO-CH_2-COOC_2H_5 \xrightarrow{NaOH, H_2O} A$. The product '$A$' in the reaction is

Hence the product $(Y)$ in the above sequence of reactions,is

In the reaction sequence,$[X]$ is a ketone:
$[X] \xrightarrow{KMnO_4/OH^{-}/\Delta} HOOC-(CH_2)_3-CH(CH_3)-COOH$
$[X]$ will be:

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 product of the following reaction is :