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 factor does not contribute for maintaining occlusal stability? \nSelect and explain. \nA. Embrasures, B. Tooth structure, C. Loss of teeth, D. Periodontal disease', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]