Which of the following reaction are esterification?

CH3CH2COOH + CH3OH = CH3CH2COOCH3 + H2O
CH3CH2OH = CH2CH2 + H2O
CH3CCH + HBr = CH3CBrCH2
CH3CH2CH2CH3 + Br2 = CH3CH2CH2CH2Br + HBr

The reaction CH3CH2COOH + CH3OH = CH3CH2COOCH3 + H2O is an esterification reaction.