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: Pathology
What is the pH at which initiation of caries begins? 
Select and explain. 
A. 4.3 - 4.5, B. 5.2 - 5.5, C. 4.9 - 5.1, D. 3.5 - 4. 5
B: 5.2 - 5.5
Answer: B: 5.2 - 5.5 
Explanation: None