—— Do you mind my opening the window? It’s a bit hot in here.—— as a matter of factA. Go

问题补充：

—— Do you mind my opening the window? It’s a bit hot in here.

——, as a matter of fact

A. Go ahead

B. Yes, my pleasure

C. Yes, I do

D. Come on

答案：

A. Go ahead

B. Yes, my pleasure

(答案→)C. Yes, I do

D. Come on

解析：根据答语中的as a matter of fact “实际上”，可知作者很介意。