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': 'Laser welding: \nSelect and explain. \nA. Involves high heat generation, B. Can be done with pure titanium, C. Is not used in dentistry, D. Can he done with pure gold', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]