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
According to Black's classification, caries on lingual pits of maxillary central incisors are: 
Select and explain. 
A. Class I, B. Class II, C. Class III, D. Class IV
A: Class I
Answer: A: Class I 
Explanation: None