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': 'Cryptogenic organising pneumonia Is characterised by all of the following except \nSelect and explain. \nA. Migratory pulmonary opacities, B. Obstructive pattern of pulmonary function, C. Aerial hypoxemia, D. Good response to coicosteroids', 'role': 'user'}, {'content': "Answer: B \nExplanation: In cryptogenic organizing pneumonia,pulmonary function is impaired with a restrictive defect and aerial hypoxaemia,being most common.Chest X ray shows bilateral,patchy/diffuse,recurrent & migratory pulmonary opacities.These changes are more frequent in the periphery of the lung and in the lower lung zone.Glucocoicoid therapy induces clinical recovery in two-thirds of patients. Reference:Harrison's medicine-18th edition,page no:2166,2167.", 'role': 'assistant'}]