You can depend on whatever promise he makes. A. / B. why C. when D. whose

问题补充：

You can depend on whatever promise he makes.

A. /

B. why

C. when

D. whose

答案：

(答案→)A. /

B. why

C. when

D. whose

解析：he makes是定语从句, 从句前省略了关系代词that.