Butan-2-one is warmed with $I X_{2} / NaOH$ . The yellow precipitate is filtered off and the filtrate is acidified with dilute HCl. The organic compound obtained from the filtrate is

Answer: A

The

CH X_{3} CO X^{-}

group of

CH X_{3} COCH X_{2} CH X_{3}

undergoes the haloform reaction: the yellow solid is

CHI X_{3}

and the other fragment is

CH X_{3} CH X_{2} COO X^{-} Na X^{+}

. Acidification gives

CH X_{3} CH X_{2} COOH

, propanoic acid.