The correct option is B Esterification
Esters are formed by the reaction of an acid and an alcohol. Ethanoic acid reacts with absolute ethanol in the presence of a mineral acid catalyst (usually sulphuric acid) to give an ester. Hence the given reaction is called an esterification.
CH3COOH+CH3CH2OH+Acid catalyst→CH3COOC2H5 (Ester)