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: Dental
Surface of NiTi wire is 
Select and explain. 
A. Rougher than beta titanium wire, B. Rougher than stainless steel wire, C. Both of the above, D. None of the above
C: Both of the above
Answer: C: Both of the above 
Explanation: None