The silver mirror test is used to detect which of the following?

How will you convert butan-$2$-one to propanoic acid?
$CH_3-CH_2-CO-CH_3 + I_2 + NaOH$ $\rightarrow C_2H_5CO_2^-Na^+ + CHI_3$ $\xrightarrow{H^+} C_2H_5COOH$

An organic compound with the molecular formula $C_9H_{10}O$ forms a $2,4-DNP$ derivative,reduces Tollen's reagent and undergoes Cannizzaro reaction; on vigorous oxidation it gives $1,2-$benzenedicarboxylic acid. The structure of the organic compound is:

In the given Cannizzaro reaction,the slowest step is:
$2PhCHO \xrightarrow{KOH} PhCH_2OH + PhCOO^-$

Which will give silver mirror test with Tollens reagent?

Schiff's reagent gives pink colour with