Iodoform test is not given by

An organic compound $X$ is oxidised by using acidified $K_2Cr_2O_7$ solution. The product obtained reacts with phenyl hydrazine but does not give the silver mirror test. The compound $X$ is,

The reagent used to distinguish between acetaldehyde and benzaldehyde is

What are $X$ and $Y$ in the following reaction sequence?
$Propene$ $\xrightarrow{HBr} A$ $\xrightarrow[Dry \ ether]{Mg} B$ $\xrightarrow[2. H_3O^{+}]{1. X} Y$

Match the reactions given in Column-$I$ with the suitable reagents given in Column-$II$.

Column-$I$ (Reactions)	Column-$II$ (Reagents)
$(A).$ Benzophenone $\to$ Diphenylmethane	$(1).$ $LiAlH_4$
$(B).$ Benzaldehyde $\to$ $1-$Phenylethanol	$(2).$ $DiBAL-H$
$(C).$ Cyclohexanone $\to$ Cyclohexanol	$(3).$ $Zn(Hg) / \text{Conc. } HCl$
$(D).$ Phenyl benzoate $\to$ Benzaldehyde	$(4).$ $CH_3MgBr$

Reduction of $>C=O$ to $CH_2$ can be carried out with: