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
[{'content': 'Dryopithecus pattern is the characteristic feature of: \nSelect and explain. \nA. Permanent mandibular 1st molar., B. Permanent mandibular 3rd molar., C. Permanent maxillary 2nd molar., D. Permanent maxillary canine.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: In a mandibular first molar mesiolingual cusp joins the distobuccal cusp along the floor of the central fossa, this is known as dryopethicus pattern.', 'role': 'assistant'}]