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
Fibroblasts in cell-rich zone primarily secretes: 
Select and explain. 
A. Type I collagen, B. Type VI collagen, C. Type V collagen, D. Type IV collagen
A: Type I collagen
Answer: A: Type I collagen 
Explanation: None