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
The main bulk of dentin is formed by 
Select and explain. 
A. Peritubular dentin, B. Mantle dentin, C. Inter tubular dentin, D. Predentin
C: Inter tubular dentin
Answer: C: Inter tubular dentin 
Explanation: None