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': 'Extrusive movements ideally would produce no areas of compression within PDL, but will produce: \nSelect and explain. \nA. Only contusion, B. Only tension, C. Only retraction, D. Only extraction', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Extrusion is defined as the axial movement of the tooth\xa0along the long axis towards the coronal part.\xa0\nFeatures of Extrusion:\n\nForce required: 35–60 g\nLoading pattern: No areas of compression in PDL.\n\nOnly stretched areas/tension.', 'role': 'assistant'}]