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': 'Isolated systolic hypeension is defined as: \nSelect and explain. \nA. SBP>140, DBP<90, B. SBP>140, DBP<80, C. SBP>150, DBP<90, D. SBP>150, DBP<90', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Isolated systolic hypeension is defined as systolic BP greater than 140 and diastolic BP less than 90. Ref: Park 21st edition, page 344.', 'role': 'assistant'}]