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': 'Simple anchorage refers to \nSelect and explain. \nA. Closure by tipping, B. Closure by bodily movement, C. Closure by rotation, D. Closure by intrusion', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]