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': 'Friction locked pins are usually retained by \nSelect and explain. \nA. Threads on pin, B. Resiliency of dentine, C. Luting cement, D. Channel depth', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]