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: Surgery
[{'content': 'Which of the following is not a risk factor for breast carcinoma? \nSelect and explain. \nA. Saturated fatty acids, B. Early menopause, C. Nulliparous women, D. Oestrogen unopposed by progesterone', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Causes for breast carcinoma are -\n\nOestrogen exposure, unopposed by progesterone\nNulliparous women\nMutations in the\xa0 BRCA1 and BRCA2 genes\xa0\nEarly menarche/late menopause\xa0\nFamily history\xa0\nSaturated dietary fats\nPrevious benign atypical hyperplasia', 'role': 'assistant'}]