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': 'Largest cusp in permanent mandibular first molar is: \nSelect and explain. \nA. Mesiobuccal, B. Distobuccal, C. Mesio lingual, D. Distal', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]