To improve the quality of our products we asked anyone had used the products for suggest

问题补充：

To improve the quality of our products, we asked anyone had used the products for suggestions.

A. whoever

B. who

C. which

D. whichever

答案：

A. whoever

(答案→)B. who

C. which

D. whichever

解析：考查定语从句。本定语从句的先行词是anyone，定语从句中缺少主语，故使用who指代先行词anyone在句中做主语。句意：为了提高产品的质量，我们想那些使用过我们产品的人征求建议。故B正确。