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': "Which of the following fluid should not be used in first 24 hrs after operation: \nSelect and explain. \nA. 5% dextrose., B. Isotonic saline, C. Ringer's lactate, D. All of the above", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]