—What do you think of this matter? —This is a matter of importance. I think.A. especial B.

问题补充：

—What do you think of this matter? —This is a matter of importance. I think.

A. especial

B. quiet

C. rather

D. special

答案：

A. especial

B. quiet

(答案→)C. rather

D. special

解析：本题的含义是这是一个相当重要的问题，，rather表示相当的意思，修饰名词，故本题选C。