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
[{'content': 'NiTi alloys have: \nSelect and explain. \nA. Shape memory, B. Hyper rigidity, C. Corrosion resistance, D. Weldable properties', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]