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
The first permanent tooth to erupt in the oral cavity
is the: 
Select and explain. 
A. Mandibular central incisor, B. Mandibular first molar, C. Maxillary central incisor, D. Maxillary first molar
B: Mandibular first molar
Answer: B: Mandibular first molar 
Explanation: None