This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Medicine
[{'content': 'What is the definitive method of diagnosing pulmonary embolism? \nSelect and explain. \nA. Ventilation perfusion imaging, B. Positron Emission Tomography, C. High Resolution CT, D. Pulmonary angiography', 'role': 'user'}, {'content': "Answer: D \nExplanation: CT pulmonary angiography is the first line diagnostic test for pulmonary embolism.It has the advantages of visualising the distribution and extent of the embolism,or highlighting an alternative diagnosis,such as consolidation,pneumothorax or aoic dissection. Reference:Davidson's medicine-22nd edition,page no:722.", 'role': 'assistant'}]