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
Lactobacillus count AFTER CARIES ACTIVITY test is 10,500CFU. What is the rate of caries progression ? 
Select and explain. 
A. Slight, B. Mild, C. Moderate, D. Severe
D: Severe
Answer: D: Severe 
Explanation: None