Two aliphatic aldehydes $\mathbf{P}$ and $\mathbf{Q}$ react in the presence of aqueous $\mathrm{K}_2 \mathrm{CO}_3$ to give compound $\mathbf{R}$, which upon treatment with HCN provides compound $\mathbf{S}$. On acidification and heating, $\mathbf{S}$ gives the product shown below :

Two aliphatic aldehydes $\mathbf{P}$ and $\mathbf{Q}$ react in the presence of aqueous $\mathrm{K}_2 \mathrm{CO}_3$ to give compound $\mathbf{R}$, which upon treatment with HCN provides compound $\mathbf{S}$. On acidification and heating, $\mathbf{S}$ gives the product shown below :

Two aliphatic aldehydes $\mathbf{P}$ and $\mathbf{Q}$ react in the presence of aqueous $\mathrm{K}_2 \mathrm{CO}_3$ to give compound $\mathbf{R}$, which upon treatment with HCN provides compound $\mathbf{S}$. On acidification and heating, $\mathbf{S}$ gives the product shown below :

Match each of the compounds given in Column I with the reaction(s), that they can undergo, given in Column II.

	Column I		Column II
(A)		(P)	Nucleophilic substitution
(B)		(Q)	Elimination
(C)		(R)	Nucleophilic addition
(D)		(S)	Esterification with acetic anhydride
		(T)	Dehydrogenation