Vanillin (L)  $C_8{H}_8{O}_3$ is isolated from vanilla beans. It gives an intense colour with  $FeC{\mathcal{l}}_3$   and a positive Tollen's test. It is not steam-distilled and does not react with HCl. It goes through the following steps: 

Among the following pair(s) which can be distinguished by aq. $NaHC{O}_3$  is/are: