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': 'The area, which is most prone to infection \nSelect and explain. \nA. Marginal gingiva, B. Sulcular epithelium, C. Interdental col, D. Attached gingiva', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]