The reaction $CH_3-C(=O)-CH_2-C(CH_3)_2-CHO \xrightarrow{KOH, H_2O} (A)$; Product $A$ is

Which of the following ketones has the maximum dipole moment?

$A$ $(C_3H_6O)$ $\xrightarrow{NaCN/H_2SO_4}$ cyanohydrin of $A$. If the cyanohydrin is optically active,then the possible structure of $A$ is:

The ratio $x / y$ on completion of the above reaction is $.........$.

An ester $(A)$ with molecular formula $C_9H_{10}O_2$ was treated with excess of $CH_3MgBr$ and the complex so formed was treated with $H_2SO_4$ to give an olefin $(B)$. Ozonolysis of $(B)$ gave a ketone with molecular formula $C_8H_8O$ which shows positive iodoform test. The structure of $(A)$ is

An optically active alkyl bromide $C_4H_9Br$ reacts with ethanolic $KOH$ to form major compound $[A]$,which reacts with bromine to give compound $[B]$. Compound $[B]$ reacts with ethanolic $KOH$ and sodamide to give compound $[C]$. One molecule of water adds to compound $[C]$ on warming with mercuric sulphate and dilute sulphuric acid at $333 \text{ K}$ to form compound $[D]$. The functional group in compound $[D]$ will be confirmed by: