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': 'Labial bar is indicated when ? \nSelect and explain. \nA. There is diastema, B. There is labial inclination of teeth, C. There is lingual inclination of teeth, D. There is periodontally weak teeth', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Rest all are contraindications for labial bar.', 'role': 'assistant'}]