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': 'Lamina densa of the gingival basement membrane is rich in \nSelect and explain. \nA. Type I and III collagen, B. Type III collagen, C. Type IV collagen, D. Type I collagen', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]