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
Commonest type of lung carcinoma in nonsmokers is - 
Select and explain. 
A. Squamous cell carcinoma, B. Adenocarcinoma, C. Alveolar cell carcinoma, D. Small cell carcinoma
B: Adenocarcinoma
Answer: B: Adenocarcinoma 
Explanation: None