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 premolars is usually the smallest: 
Select and explain. 
A. Maxillary first, B. Maxillary second, C. Mandibular first, D. Mandibular second
C: Mandibular first
Answer: C: Mandibular first 
Explanation: None