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: Medicine
[{'content': 'In the pulmonary function test shown in the colour palate; green line shows: \nSelect and explain. \nA. COPD, B. Normal lung function, C. Tracheal obstruction, D. Pulmonary fibrosis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]