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': 'Most diagnostic of pulmonary embolism in a high-risk case is: \nSelect and explain. \nA. Multidetector CT angiography, B. Catheter angiography, C. D-dimer, D. Ventilation perfusion scan', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. Multidetector CT angiography', 'role': 'assistant'}]