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: Unknown
[{'content': 'Coincidental malignancy in upper respiratory tract with inverted papillomais: \nSelect and explain. \nA. 2%, B. 5%, C. 4%, D. 0.10%', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Coincidental malignancy in upper respiratory tract with inverted papillomais 4 %.\nMalignant transformation of tumoritself is 8 %', 'role': 'assistant'}]