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
Opaque white areas covering more than 25% but less than 50% of the tooth surface is given the Dean's score of: 
Select and explain. 
A. 1, B. 2, C. 3, D. 4
B: 2
Answer: B: 2 
Explanation: None