This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiration, Subject name: Pathology
[{'content': 'Worst prognosis of associated with which of the following lung cancer? \nSelect and explain. \nA. Small cell carcinoma, B. Adenocarcinoma, C. Squamous cell carcinoma, D. Oat cell carcinoma', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e. Small cell carcinoma * Small cell carcinomas are the most aggressive of lung tumors, metastasize widely and are virtually incurable by surgical means.", 'role': 'assistant'}]