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': 'After the tooth emerges to the occlusal plane the clinical\ncrown height increases by: \nSelect and explain. \nA. Passive eruption, B. Active eruption, C. Post-emergence growth spurt, D. Juvenile occlusal equilibrium', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]