This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gynaecological oncology, Subject name: Gynaecology & Obstetrics
[{'content': 'Following are precursors of endometrial carcinoma except : \nSelect and explain. \nA. Atypical adenomatous hyperplasia, B. Atrophic endometrium, C. Adenocarcinoma in situ, D. Cystic hyperplasia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Endometrial atrophy is the most common cause of post menopausal bleeding Reference :Textbook of Gynaecology; Sheila balakrishnan; 2nd edition; Pg no:245', 'role': 'assistant'}]