Concept:Ethanoic acid reacts with an alkanol to form an ester, which has a pleasant, sweet smell.Explanation:Ethanoic acid is a carboxylic acid.Carboxylic acids react with alcohols to form esters.Alkanes, alkanals, and alkynes do not give this esterification reaction with ethanoic acid.The general reaction is:CH3COOH+ROH→CH3COOR+H2OHere, ROH represents an alkanol.The product CH3COOR is an ester.Esters are known for their sweet and fruity odours.Therefore, the compound that reacts with ethanoic acid to give a sweet smelling liquid is an alkanol.Answer:B. Alkanol