This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Angiography, Subject name: Radiology
[{'content': 'Gold Standard investigation for pulmonary Thromboembolism? \nSelect and explain. \nA. V/Q SCAN, B. CECT, C. Angiography, D. MRI', 'role': 'user'}, {'content': 'Answer: C \nExplanation: *Gold standard is Pulmonary Angiography. *IOC - CT Angio. CE pulmonary angiogram showing hypodense thrombus in left main pulmonary aery.', 'role': 'assistant'}]