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: Surgery
[{'content': 'An accurate method of measuring fluid replacement following acute blood loss is to check the: \nSelect and explain. \nA. Hematocrit, B. Hemoglobin, C. Blood pressure, D. Central venous pressure', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]