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': 'Most efficient orthodontic tooth movement is obtained by: \nSelect and explain. \nA. Light continuous force, B. Large intermittent force, C. Light interrupted force, D. Heavy continuous force', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]