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': "Differential force concept is mainly used in \nSelect and explain. \nA. Straight wire appliance, B. Lingual appliance, C. Begg's Light wire appliance, D. Frankel appliance", 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]