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
One of the following condition is not associated with clubbing : 
Select and explain. 
A. Primary biliary cirrhosis, B. Chronic bronchitis, C. Cryptogenic fibrosing alveolitis, D. Central bronchiectasis
B: Chronic bronchitis
Answer: B: Chronic bronchitis 
Explanation: Answer is B (Chronic bronchitis): Chronic bronchitis does not cause clubbing Some causes of finger clubbing Respiratory Cardiovascular Bronchial carcinoma, especially epidermoid (squamous cell) type (major cause) Cyanotic hea disease Chronic suppurative lung disese Subacute infective endocarditis Bronchiectasis Lung abscess Miscellaneous Empyema Congenital -- no disease Cirrhosis Pulmonary fibrosis (e.g. cryptogenic fibrosing alveolitis) Inflammatory bowel disease Pleural and mediastinal tumours (e.g. mesothelioma) Primary billiary cirrhosis Crvptogenic organizing pneumonia