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: Anatomy
[{'content': 'Diffusion capacity for carbon monoxide is decreased in all of the following except \nSelect and explain. \nA. Chronic bronchitis, B. Emphysema, C. Interstitial lung disease, D. Pulmonary embolism', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Diffusion capacity for carbon monoxide (DLCO) is usually nirmln in chronic bronchitis and other obstructive lung disease with the exception of empyseemp where it is decreased. Ref Harrison 19th edition pg 1710', 'role': 'assistant'}]