73. Arrange the carboxylic acid derivatives below in order of increasing reactivity towards nucleophilic acyl substitution. (A) 1 ＜ 2 ＜3 (B) 1 ＜ 3 ＜ 2 (C) 2 ＜ 1 ＜ 3 (D) 2 ＜ 3 ＜ 1