$CH_3CHO$ $\xrightarrow{HCN} A$ $\xrightarrow{H_3O^+} B$. The product $B$ is

An alkene $(A)$ $C_{16}H_{16}$ on ozonolysis gives only one product $(B)$ $C_8H_8O$. $(B)$ can also be obtained by the hydrolysis of the product obtained from the reaction between cyanobenzene and $CH_3MgBr$. $(A)$ shows geometrical isomerism and decolourises $Br_2$ water. $(B)$ on treatment with $SeO_2$ produces $(C)$. Which statement is not correct about $(C)$?

What are $X$ and $Y$ in the following reaction sequence?
$Toluene$ $\xrightarrow{X} Benzaldehyde$ $\xrightarrow{HNO_3 + H_2SO_4, 273-283 \ K} Y$

Identify the major product of the following reaction:

For the reduction of ketones to hydrocarbon,the appropriate agent is

The reaction of chloroform with acetone gives ...................