单选题 Classmate A: Damn it. My mailbox got packed with loads of junks.
Classmate B: You can use Active Email Monitor, a Spam filter, to create any number of filters and so cut down on the amount of junk emails you receive.
Classmate A: Thank you. You really help me a lot.
Classmate B: ______.
A. It's my pleasure B. It's my duty C. It's my job D. It'smy fault

【正确答案】 A

【答案解析】[解析] It's my pleasure是对他人致谢的一种回应语，表示“没什么，乐意效劳”的意思；It's my duty是中式英语，英文的意思是“这是我不得不做的事”，这个用语在此情境下不得体；It's my job是“这是我分内之事，这是我应该做的”的意思，在此情境下不如It's my pleasure礼貌和得体；It's my fault是表示承担责任的用语，表达“这是我的错，我应受责备”的意思。