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 tooth is not having 5 cusps? 
Select and explain. 
A. Mandibular 2nd Molar, B. Mandibular 1st Molar, C. Mandibular 3rd Molar, D. Maxillary 1st Molar
A: Mandibular 2nd Molar
Answer: A: Mandibular 2nd Molar 
Explanation: None