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': 'Chin cap is used in \nSelect and explain. \nA. Class I, B. Class II, C. Skeletal class III, D. Dental class III', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Chin cap was introduced by Oppenheim. It delivers a force of 800 - 1200 (400 - 600 gms/side). The patient is asked to wear the appliance for 12-14 hours/ day.', 'role': 'assistant'}]