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
Coincidental malignancy in upper respiratory tract with inverted papillomais: 
Select and explain. 
A. 2%, B. 5%, C. 4%, D. 0.10%
C: 4%
Answer: C: 4% 
Explanation: Coincidental malignancy in upper respiratory tract with inverted papillomais 4 %.
Malignant transformation of tumoritself is 8 %