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: Radiology
[{'content': 'Which cancer is predisposed by radon exposure? \nSelect and explain. \nA. Lung, B. Cervix, C. Oral cavity, D. Bladder', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. Lung', 'role': 'assistant'}]