c
\(\mathop {2 - Methyl\,\,butanoic\,\,acid}\limits_{( \pm )}  + \) \(\mathop {2 - Butanol}\limits_{( \pm )} \) \(\overset {esterification} \longleftrightarrow \)  ester \(+\) \(H_2O\) \(\to \) possible configuration of ester will be \(\to \) ester consist of two
stereo centres \(\to \) chiral center during whole reaction not affected that's why all esters are optically active.