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': 'Shape memory in NiTi is because of stress induced form \nSelect and explain. \nA. Austenite to martensite, B. Martensite to austenite, C. Ferrite to austenite, D. Austenite to ferrite', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]