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 is not a component of cell rich zone \nSelect and explain. \nA. Collagen Type 1, B. Collagen type 3, C. Collagen type 5, D. Stem cells', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Collagen fibers type 1 and type 3 are present in cell rich zone while type 5 is absent.', 'role': 'assistant'}]