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
With slowly advancing enamel caries and rapid involvement of dentin type of dentin formed is 
Select and explain. 
A. Secondary, B. Tertiary, C. Reparative, D. Sclerotic
D: Sclerotic
Answer: D: Sclerotic 
Explanation: None