The compound that does not answer iodoform test is

Step-by-step solution

The iodoform test is given by compounds containing a CH₃-CO- group (methyl ketones and acetaldehyde) or a CH₃-CH(OH)- group (which can be oxidized to a methyl ketone). Ethanal ( CH₃CHO ) contains a CH₃-CO- group, hence it gives the iodoform test. Acetone ( CH₃COCH₃ ) contains a CH₃-CO- group, hence it gives the iodoform test. Acetophenone ( C₆H₅COCH₃ ) contains a CH₃-CO- group, hence it gives the iodoform test. Ethanoic acid ( CH₃COOH ) is a carboxylic acid. In the presence of the basic reagent ( NaOH + I₂ ), it un