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: Social & Preventive Medicine
[{'content': 'In a normal curve, the area of one standard deviation around the mean includes which of the following per cent of values in a distribution - \nSelect and explain. \nA. 0.486, B. 0.683, C. 0.954, D. 0.997', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]