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 type of anchorage in which two groups of teeth move in equal and opposite direction is called as \nSelect and explain. \nA. Stationary, B. Reciprocal, C. Simple, D. Compound', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]