Acyl nucleophilic substitution (SNAC) (SNAE)

Which of the following is the correct nucleophilic substitution ?

Nucleophilic Substitution Reaction

Nucleophilic Addition Elimination Reaction : acyl nucleophilic substitution on carboxylic acids and dervatives(SNAE/SNAC)-3) carboxylic acid,4)anhydrides(Symmetrical and unsymmetrical),5)benzene sulphonyl chloride,6) cyanides and isocyanides,7) amides

Give the decreasing order of reactivity of the following towards hydrolysis (or nucleophilic acyl substitution) : (i) (I) PhCOOMe (II) (II) (IV) (ii) (I) PhCOCl (II) (iii) (I) PhCOCl (III) Me_2 CHCOCl (IV) Me_3 C-COCl . (b) Give the decreasing order of transacylation reactivities and nucleophilic acyl substitution reactivities fo the following : (I) MeCOCl (II) MeCON_3 (III) (MeCO)_2 O (IV) MeCOOMe (V) MeCONH_2 .

Which of the following statements are correct about nucleophilic acyl substitution ?