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': 'In a chronic smoker, a highly malignant aggressive and metastatic lung carcinoma is - \nSelect and explain. \nA. Squamous cell Carcinoma, B. Small cell Carcinoma, C. Adenocarcinoma, D. Large cell carcinoma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]