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': 'Which of the following factors are primarily contributory to the shedding of deciduous tooth? \nSelect and explain. \nA. Hydrostatic, B. Vascular pressure, C. Oncotic pressure, D. Masticatory pressure', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]