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 Permanent tooth has most prominent transverse ridge 
Select and explain. 
A. Lower 1stpremolar, B. Upper 1stpremolar, C. Lower 1st molar, D. Upper 2ndmolar
A: Lower 1stpremolar
Answer: A: Lower 1stpremolar 
Explanation: None