The compound that will give iodoform on treatment with alkali and iodine is

Iodoform test is given by those compounds which has -COCH₃ group and also those alcohols which produces the -CH₃CO group on oxidation. So here in this case, acetone has -COCH₃ group and ethanol on oxidation produces -CH₃CHO so it also has -COCH₃ group but in diethyl ketone we have CH₃CH₂COCH₂CH₃ means we have ethyl group so that is why it cannot gives iodoform test.