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
When viewed occlusally, a primary mandibular second molar closely resembles which of following mandibular teeth? 
Select and explain. 
A. Permanent second molar, B. Permanent first molar, C. Second premolar, D. Primary first molar
B: Permanent first molar
Answer: B: Permanent first molar 
Explanation: None