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
In the pulmonary function test shown in the colour palate; green line shows: 
Select and explain. 
A. COPD, B. Normal lung function, C. Tracheal obstruction, D. Pulmonary fibrosis
A: COPD
Answer: A: COPD 
Explanation: None