傅-克酰化反应中，酰化剂的活性次序由强到弱正确的是（）

A. CH3COI>CH3COBr>CH3COCl>CH3CF
B. CH3CF>CH3COCl>CH3COBr>CH3COI
CH3COI>CH3COCl>CH3COBr>CH3CF
D. CH3COI>CH3COBr>CH3CF>CH3COCl