—Could I borrow the book by Mo Yan?— .A. Yes you couldB. You’re welcomeC. By all means D.

问题补充：

—Could I borrow the book by Mo Yan?

— .

A. Yes, you could

B. You’re welcome

C. By all means

D. I am afraid so

答案：

A. Yes, you could

B. You’re welcome

(答案→)C. By all means

D. I am afraid so

解析：交际用语。A是的，你可以；B不客气；C尽一切办法；D恐怕如此。句意：——我能借莫言的书吗？——我会尽力的。故C正确。