I really can’t thank you enough， sir. — .
A. That’s the most I could do
B. I’m glad to have been of help
C. No problem
D. With pleasure
网友回答
A. That’s the most I could do
(答案→)B. I’m glad to have been of help
C. No problem
D. With pleasure
解析：句意：上文，先生，我再怎样感谢你都不为过。下文，我很高兴提供了帮助。That’s the most I could do那是我所能做的最多的 I’m glad to have been of help我很高兴提供了帮助 No problem没事儿 With pleasure高兴地，选B。