A、Twenty-four credits. B、Twelve credits. C、Three Credits. D、Thirty-six credits. D对话中女士说，(要取得硕士学位)需要36个学分，故选D。

M: Good morning, Dr. Smith. My name is Peter. I am a freshman in your department. There are a few things that I am not quite sure of and I do need your advice.
W: Thank you very much for your trust, Peter. As your academic advisor I will try my best to help you.
M: Thanks. It’s about my major...
W: Well, what’s the matter?
M: I used to major in English, but now I have made up my mind to switch to Applied Linguistics, concentrating on Teaching English as a Foreign Language.
W: So you want to switch majors?
M: Yes. But I wonder if it is possible.
W: Well, usually we allow it, as long as you have enough credits.
M: That’s good news for me. I’m not interested in literature and that sort of thing. I want to be a real teacher, Professor. But I’m worried about the make-up credits.
W: You usually do have to make up some credits when you switch majors. Are you OK on credits?
M: Not too many. I’ll have to add about 12 credits as far as I can. figure from my transcript. Would you please let me know how many credits are required to get a master’s degree?
W: Usually thirty-six credits are needed, ff you take five courses per term, you’ll have enough credits after just two semesters. Usually each course is worth three credits. To get the six remaining credits you either prepare a thesis or take two more courses.
M: Is there anything else besides the 36 credits for the master’s?
W: You have to have an oral defense．
M: I see．I really appreciate your help，Professor．
W: Glad I can help．Good luck．Peter．