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': 'Factors that protect against endometrial cancer \nSelect and explain. \nA. Obesity, B. Smoking, C. Nulliparity, D. Diabetes', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Factors that increase\n\t\t\tendometrial cancer\n\t\t\trisk\nFactors that protect\n\t\t\tagainst endometrial\n\t\t\tcancer\n\n\nObesity\nHysterectomy\n\n\nDiabetes\nCombined oral contraceptive pill\n\n\nNulliparity\nProgestin - based\n\t\t\tContraceptives, including injectables\n\n\nLate menopause\n\t\t\t> 52 years\nIntrauterine device, including Cu-IUD and LNG-IUS\n\n\nUnopposed oestrogen\n\t\t\ttherapy\nPregnancy\n\n\nTamoxifen therapy\nSmoking\n\n\n\nFamily history of\n\t\t\tcolorectal and\n\t\t\tendometrial cancer', 'role': 'assistant'}]