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
Secondary dentin formation 
Select and explain. 
A. Greater at pulp floor, B. Greater at pulp roof, C. Same at floor and roof, D. None of the above
A: Greater at pulp floor
Answer: A: Greater at pulp floor 
Explanation: None