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': 'Pulmonary thromboembolism on V-Q scan is suggested by: \nSelect and explain. \nA. Ventilation defect with normal perfusion, B. Perfusion defect with normal ventilation, C. Perfusion defect with ventilation defect, D. Normal perfusion and ventilation', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Perfusion defect with normal ventilation', 'role': 'assistant'}]