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
A change in color of medium from green to yellow after 48 hours during Snyder’s test is indicative of? 
Select and explain. 
A. No caries activity, B. Slight caries activity, C. Marked caries activity, D. Definite caries activity
D: Definite caries activity
Answer: D: Definite caries activity 
Explanation: None