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': 'Investigation of choice for High-risk cancer in the female is: \nSelect and explain. \nA. MRI, B. CT-PET, C. Mammography, D. USG', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]