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: Radiology
[{'content': 'Best imaging modality in bronchogenic carcinoma- \nSelect and explain. \nA. CT, B. MRI, C. Bronchoscopy, D. None', 'role': 'user'}, {'content': 'Answer: A \nExplanation: CT scan is the investigation of choice for pulmonary malignancy except for superior sulcus or pancoast tumor, where\xa0MRI is the investigation of choice.', 'role': 'assistant'}]