$CH_3CH_2C \equiv N \xrightarrow{X} CH_3CH_2CHO$. The compound $X$ is:

Which of the following gives an aldehyde on dry distillation?

Consider the following statements. Acetophenone can be prepared by:
$1$. Oxidation of $1$-phenylethanol
$2$. Reaction of benzaldehyde with methyl magnesium bromide
$3$. Friedel-Crafts reaction of benzene with acetyl chloride
$4$. Distillation of calcium benzoate

What are $X$ and $Y$ in the following reaction sequence?
$C_5H_{12}O$ $\xrightarrow[573 \ K]{Cu} C_5H_{10}$ $\xrightarrow[\text{(ii) } Zn/H_2O]{\text{(i) } O_3} X + Y$

$CH_3-CH(OH)-CN$ is

Which among the following compounds is treated with benzonitrile in dry ether followed by acid hydrolysis to obtain benzophenone?