The given reaction takes place in the presence of the I₂ and NaOH. These two act as an oxidizing agent and convert ketones into a carboxylic acid (the number of carbon in parent chain reduces by one).

These reagents are most suitable reagents as they don’t affect the double C=C bond present in the molecules, whereas all the other reagent affects the double C=C bond.

Step 1 Mechanism;

Step 2 Mechanism;

Step 3 Mechanism;

This reaction is known as oxidation of methyl ketone by haloform reaction.