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': 'Stress in cold working can be relieved by: \nSelect and explain. \nA. Age hardening, B. Annealing, C. Hydrochloric acid, D. Beating', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]