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
[{'content': 'Commonest type of lung carcinoma in nonsmokers is - \nSelect and explain. \nA. Squamous cell carcinoma, B. Adenocarcinoma, C. Alveolar cell carcinoma, D. Small cell carcinoma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]