This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
[{'content': 'Which is not used in the treatment of endometriosis : \nSelect and explain. \nA. Danazol, B. Tamoxifen, C. Medroxyprogesterone, D. GnRH analogues', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Tamoxifen', 'role': 'assistant'}]