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': 'Of the following the most significant risk factor for developing breast cancer is- \nSelect and explain. \nA. The presence of sclerosing adenosis, B. Nullipartiy, C. Atypical lobular hyperplasia, D. Atypical ductal hyperplasia', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]