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 doesn't increase the risk of Ca breast? \nSelect and explain. \nA. Nulliparity, B. Multiparity, C. Female sex, D. Women who avoid breast feed", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Family history of Ca breast in first degree relatives is also a risk factor for Ca breast. Ref: Manipal Manual of Surgery, Page 260.', 'role': 'assistant'}]