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
Advantage of NiTi over K-files? 
Select and explain. 
A. Increased flexibility, B. Low resiliency, C. Resistance to breakage, D. Less expensive
A: Increased flexibility
Answer: A: Increased flexibility 
Explanation: None