This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Breast, Subject name: Surgery
[{'content': 'Best definitive investigation for carcinoma breast is? \nSelect and explain. \nA. Biopsy, B. FNAC, C. USG, D. Mammography', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) BiopsyRef: Bailey & Love 25th ed. / 289, 290', 'role': 'assistant'}]