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
Most difficult access cavity preparation is in 
Select and explain. 
A. Mandibular incisors, B. Mandibular Canine, C. Mandibular premolar, D. Mandibular molar
A: Mandibular incisors
Answer: A: Mandibular incisors 
Explanation: None