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
Nickel-Titanium alloy has 
Select and explain. 
A. unreliable spring back, B. low spring back, C. minimal spring back, D. none of the above
D: none of the above
Answer: D: none of the above 
Explanation: None