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
Localized formation of dentin on the pulp-dentin border formed in reaction to caries or restorative procedures is known as 
Select and explain. 
A. Tertiary dentin, B. Secondary dentin, C. Primary dentin, D. Interglobular dentin
A: Tertiary dentin
Answer: A: Tertiary dentin 
Explanation: None