Acidic hydrolysis of vinyl ethers involves the addition of water across the double bond followed by the elimination of alcohol/phenol to form carbonyl compounds. In the given reaction:

The hydrolysis occurs at both vinyl ether linkages.
The left part hydrolyzes to form propanal: .
The right part hydrolyzes to form acetone: (Q).
P is an aldehyde (propanal) and Q is a ketone (acetone).
Fehling solution is used to distinguish between aldehydes and ketones. Aldehydes (except benzaldehyde) reduce Fehling solution to give a red precipitate of , while ketones do not react.
Lucas reagent is used for alcohols. 2,4-DNP reacts with both aldehydes and ketones. Saturated reacts with most aldehydes and methyl ketones, so it is not the best choice for distinguishing these specific compounds compared to Fehling solution.