Match the compounds possessing carbonyl carbon in Column-$I$ with their formulas in Column-$II$ and examples in Column-$III$:

Column-$I$ (Name)	Column-$II$ (Formula)	Column-$III$ (Example)
$(A)$ Ketone	$(i)$ $R-CO-OH$	$(p)$ $CH_3CHO$
$(B)$ Carboxylic acid	$(ii)$ $R-CO-H$	$(q)$ $CH_3COOH$
$(C)$ Amide	$(iii)$ $R-CO-R'$	$(r)$ $CH_3CONH_2$
$(D)$ Aldehyde	$(iv)$ $R-CO-NH_2$	$(s)$ $CH_3COC_2H_5$

(A) The correct matching is as follows:
$(A)$ Ketone corresponds to formula $(iii)$ $R-CO-R'$ and example $(s)$ $CH_3COC_2H_5$.
$(B)$ Carboxylic acid corresponds to formula $(i)$ $R-CO-OH$ and example $(q)$ $CH_3COOH$.
$(C)$ Amide corresponds to formula $(iv)$ $R-CO-NH_2$ and example $(r)$ $CH_3CONH_2$.
$(D)$ Aldehyde corresponds to formula $(ii)$ $R-CO-H$ and example $(p)$ $CH_3CHO$.
Therefore,the correct sequence is: $A$ $\rightarrow iii$ $\rightarrow s, B$ $\rightarrow i$ $\rightarrow q, C$ $\rightarrow iv$ $\rightarrow r, D$ $\rightarrow ii$ $\rightarrow p$.