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': 'In Stationary anchorage, anchorage is obtained from \nSelect and explain. \nA. More stable teeth, B. Extra - oral, C. Teeth from the opposite arch, D. Stationary teeth', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]