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
Which of the following is generally the longest root canal on the maxillary first molar? 
Select and explain. 
A. Mesiobuccal, B. Distobuccal, C. Palatal, D. Distolingual
C: Palatal
Answer: C: Palatal 
Explanation: None