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
Most common lung cancers in non smokers is 
Select and explain. 
A. Squamous cell carcinoma, B. Bronchoalveolar carcinoma, C. Small cell carcinoma, D. Adenocarcinoma
D: Adenocarcinoma
Answer: D: Adenocarcinoma 
Explanation: Adenocarcinoma is the most common lung cancers in non smokers.