Which of the following reagents can be used to distinguish propanal from propanone? (more than one may be correct)

Propanal is an aliphatic aldehyde and reduces Tollens reagent (silver mirror) and Fehling's solution (red $\mathrm{Cu}{}_2\mathrm{O}$); propanone does not. Both give a 2,4-DNP precipitate and both form bisulphite adducts, so those reagents cannot distinguish them.