The relative reactivities of acyl compounds towards nucleophilic substitution are in the order of
(a) Acid anhydride > Amide > Ester > Acyl chloride
(b) Acyl chloride > Ester > Acid anhydride > Amide
(c) Acyl chloride > Acid anhydride > Ester > Amide
(d) Ester > Acyl chloride > Aruide > Acid anhydride.