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': 'Long term used taxmoxifen causes : \nSelect and explain. \nA. Endometrium Ca, B. Ovary Ca, C. Cervix Ca, D. Vagina Ca', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Endometrium Ca', 'role': 'assistant'}]