Which of the following gives an aldehyde on dry distillation?

Which reagent is used in the preparation of benzaldehyde from benzene by the Gatterman-Koch reaction?

Explain different methods of formation of benzaldehyde by chemical reactions.

Identify $X$ and $Y$ in the reactions given below:

In column - $I$ reaction name,in column - $II$ reactant and in column - $III$ product are given,match column - $I$ with column - $II$ and column - $III$ with the correct option.

Column - $I$ and $II$	Column - $III$
$(A).$ Rosenmund reaction - $(i).$ $H_2, Pd, BaSO_4$	$(p).$ Benzene to benzaldehyde
$(B).$ Stephen reaction - $(iii).$ $SnCl_2, HCl$	$(q).$ Benzoyl chloride to benzaldehyde
$(C).$ Etard reaction - $(iv).$ $CrO_2Cl_2, CS_2$	$(r).$ Toluene to chromium complex
$(D).$ Gatterman-Koch reaction - $(ii).$ $CO, HCl$ anhydrous $AlCl_3/CuCl$	$(s).$ $RCN \to RCHO$

The reagents used in the Etard reaction $(I)$ and the Stephen reaction $(II)$ are: