—I really don’t know how to thank you enough .
— .
A. No problem
B. Think nothing of it
C. Not at all
D. It doesn’t matter
网友回答
A. No problem
B. Think nothing of it
C. Not at all
D. It doesn’t matter
解析：think nothing of it：used as a polite response to apologies, thanks, etc,用作回应道歉.感谢等的客气话。故选B。