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': 'Which of the following has immune function in the oral mucous membrane \nSelect and explain. \nA. Melanocyte, B. Merkel cell., C. Langerhan cell., D. Keratinocyte', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]