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 greatest advantage of using extra oral anchorage is that: \nSelect and explain. \nA. More force can be applied, B. It has a direct reciprocal action on opposing arch, C. It permits posterior movement of teeth in one arch without disturbing the opposing arch adversely, D. Any of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]