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': "Lactated Ringer's solution (Hartmann's solution) contains \nall of the following electrolytes (in approximately the\nsame proportion as human extracellular fluid) EXCEPT \nSelect and explain. \nA. Bicarbonate, B. Chloride, C. Potassium, D. Sodium", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]