An ester $(A)$ with molecular formula $C_9H_{10}O_2$ is reacted with an excess of $CH_3MgBr$. The resulting product is treated with concentrated $H_2SO_4$ to form an olefin $(B)$. Ozonolysis of $(B)$ yields a ketone with the formula $C_8H_8O$. What is the structure of $(A)$?

The products obtained in the given reactions are shown below. The number of possible products for $x$ and $y$ are:

When compound $X$ is oxidised by acidified potassium dichromate,compound $Y$ is formed. Compound $Y$ on reduction with $LiAlH_4$ gives $X$. $X$ and $Y$ respectively are:

The desired product $X$ $(\text{Ph-C(Me)(Ph)-COOH})$ can be prepared by reacting the major product of the reactions in List-$I$ with one or more appropriate reagents in List-$II$. (Given,order of migratory aptitude: $\text{aryl} > \text{alkyl} > \text{hydrogen}$)
| List-$I$ | List-$II$ |
| :--- | :--- |
| $P$. $\text{Ph}_2\text{C(OH)-C(OH)Me}_2 + \text{H}_2\text{SO}_4$ | $1$. $\text{I}_2, \text{NaOH}$ |
| $Q$. $\text{Ph}_2\text{C(NH}_2\text{)-CH(OH)Me} + \text{HNO}_2$ | $2$. $[\text{Ag(NH}_3)_2]\text{OH}$ |
| $R$. $\text{PhC(OH)(Me)-C(OH)(Ph)Me} + \text{H}_2\text{SO}_4$ | $3$. $\text{Fehling solution}$ |
| $S$. $\text{Ph}_2\text{C(Br)-CH(OH)Me} + \text{AgNO}_3$ | $4$. $\text{HCHO, NaOH}$ |
| | $5$. $\text{NaOBr}$ |

Identify the product $Y$ in the following reaction sequence:
$Benzene + CH_3CH_2CH_2Cl$ $\xrightarrow{AlCl_3} X$ $\xrightarrow{KMnO_4} Y$

Which of the following tetracarboxylic acids forms a di-anhydride upon heating?