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 mandibular labial frenum is a fibrous band that can be influenced by \nSelect and explain. \nA. Incisivus, B. Orbicularis oris, C. Caninus and incisivus, D. Incisivus and orbicularis oris', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]