c
Electron withdrawing substituent (like halogen, \(—NO_2, C_6H_5\) etc.) would disperse the negative charge and hence stabilise the carboxylate ion and thus increase acidity of the parent acid. On the other hand, electron-releasing substituents would intensify the negative charge, destabilise the carboxylate ion and thus decrease acidity of the parent acid. Electronegativity decreases in order \(F > Cl > Br\) and hence \(-I\) effect also decreases in the same order, therefore the correct option is \([FCH_2COOH > ClCH_2COOH > BrCH_2COOH > CH_3COOH]\)