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
One of the following condition Is not associated with clubbing 
Select and explain. 
A. Primary biliary cirrhosis, B. Chronic bronchitis, C. Ciyptogenic fibrosing alvcolitis, D. Central bronchiectasis
B: Chronic bronchitis
Answer: B: Chronic bronchitis 
Explanation: Chronic bronchitis does not cause clubbing Pulmonary causes of clubbing: primary and metastatic lung cancer bronchiectasis asbestosis sarcoidosis lung abscess cystic fibrosis tuberculosis mesothelioma other causes include inflammatory bowel disease,infective endocarditis,cyanotic congenital hea disease ,hepatic cirrhosis etc