Carboxylic acids have higher boiling points than aldehydes, ketones and even alcohols of comparable molecular mass. It is due to their

• A

  formation of intramolecular H-bonding

• B

  formation of carboxylate ion

• C

  more extensive association of carboxylic acid via van der Waals' forces of attraction

• D

  formation of intermolecular H-bonding.