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: Physiology
[{'content': 'A patient got his SBP reduced by 10mmHg when he stood up and he gained only 8mmHg. What was the gain? \nSelect and explain. \nA. –4, B. 4, C. –8, D. 8', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Correction here is = –8mmHg\nError persists even after correction = 10 – 8 = +2\nGain = Correction / Error\xa0\n\xa0 \xa0 \xa0 \xa0 \xa0= –8 / +2\xa0\n\xa0 \xa0 \xa0 \xa0 \xa0= –4', 'role': 'assistant'}]