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': 'Principle functions of bases are all except: \nSelect and explain. \nA. Mechanical protection of pulp, B. Chemical protection of pulp, C. Thermal protection of pulp, D. None', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]