This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Biostatistics, Subject name: Social & Preventive Medicine
[{'content': 'Systolic BP of a group of 200 people follows normal distribution. Mean BP is 120 mm Hg and standard detion 10. Which of the following is true- \nSelect and explain. \nA. 68% of people have BP between 110-130 mm Hg, B. 95% of people have BP between 110-130 mm Hg, C. 68% of people have BP between 100-140 mm Hg, D. 99% of people have BP between 100-140 mm Hg', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ref:Parks 23rd edition pg 849. 1SD : confidence limit = 68% 2SD : confidence limit = 95% 3SD : confidence limit = 99.7% 68% have BP : 110 - 130 95% have BP : 100 - 140 99.7% have BP : 90 - 150', 'role': 'assistant'}]