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': 'An attribute or exposure that is significantly associated with the development of a disease is: \nSelect and explain. \nA. Agent factor, B. Risk factor, C. Exposure factor, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]