This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: COPD and Asthma, Subject name: Medicine
All are seen in chronic bronchitis except: 
Select and explain. 
A. Cough > 3 months, B. Bronchorrhea, C. Hoover sign, D. Clubbing
D: Clubbing
Answer: D: Clubbing 
Explanation: The most common symptoms of COPD- cough, sputum production, and exeional dyspnea. Some patients with advanced disease have paradoxical inward movement of the rib cage with inspiration (Hoover's sign), the result of alteration of the vector of diaphragmatic contraction on the rib cage as a result of chronic hyperinflation. Clubbing is not seen in Chronic bronchitis