This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology and breast, Subject name: Surgery
[{'content': 'Breast cancer is conservatively treated by following methods \nSelect and explain. \nA. It is based on relative size of breast tumor, B. Radiotherapy is given, C. Chemotherapy is given, D. Surgery is best modality of treatment', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Breast conservation surgery The amount of breast tissue excised with the lesion may vary with the clinical situation, but is typically 5mm to 10mm in all directions BCS may consist of removal of tumor with 1 cm margin of normal tissue (wide local excision) or a more extensive excision of a whole quadrant of breast (Quandrantectomy) Ref: Mastery of Surgery 5th edition Pgno : 525', 'role': 'assistant'}]