Butanone is a four-carbon compound with the functional group: aldehyde, carboxylic acid, alcohol, ketone?

The correct option is D ketone. Butanone, also known as methyl ethyl ketone, is an organic compound with the formula CH3COCH2CH3. Prefix 'but' shows that it is a four-carbon compound. And suffix '-one' depicts that the functional group is ketone (C=O).