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
Score 0-0.4 in Dean's index indicates 
Select and explain. 
A. Negative mottling, B. Slight mottling, C. Moderate mottling, D. Severemottling
A: Negative mottling
Answer: A: Negative mottling 
Explanation: None