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': 'A 60 year old woman was bedridden for 2 months complains of breathlessness & chest pain, chest X-ray is normal.\nNext step is \nSelect and explain. \nA. V/Q scan, B. Echocardiography, C. Pulmonary wedge angiography, D. Pulmonary arteriography.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Clinical picture s/o P.embolism Next step should be CT Pulmo angiography - not there in option thus V/Q scan next best.', 'role': 'assistant'}]