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': 'The buccal frenal attachment of mandibular denture should \nbe trimmed and rounded to allow proper function of \nSelect and explain. \nA. Massetor, B. Buccinator, C. Triangularis, D. Zygomaticus major', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]