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
Alport syndrome is associated with defect in: 
Select and explain. 
A. Type I collagen fibers, B. Type II collagen fibers, C. Type III collagen fibers, D. Type IV collagen fibers
D: Type IV collagen fibers
Answer: D: Type IV collagen fibers 
Explanation: None