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
Clubbing is least common in - 
Select and explain. 
A. Squamous cell carcinoma, B. Adenocarcinoma, C. Small cell carcinoma of lung, D. Mesothelioma
C: Small cell carcinoma of lung
Answer: C: Small cell carcinoma of lung 
Explanation: None