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
Dryopithecus pattern is the characteristic feature of: 
Select and explain. 
A. Permanent mandibular 1st molar., B. Permanent mandibular 3rd molar., C. Permanent maxillary 2nd molar., D. Permanent maxillary canine.
A: Permanent mandibular 1st molar.
Answer: A: Permanent mandibular 1st molar. 
Explanation: In a mandibular first molar mesiolingual cusp joins the distobuccal cusp along the floor of the central fossa, this is known as dryopethicus pattern.