3.What, in general, is ihe order of decreasing reactivity of these carbonyl compounds towards nucleophilic reagents?  
(A) I＞ III ＞ V＞II＞ IV
(B) V ＞ III ＞ I ＞ II ＞ IV
(C) 1V＞II＞I＞ III ＞ V
(D) II＞ 1 ＞ V ＞ III ＞ IV
(E) III ＞ V＞ 1V＞ II ＞ L