This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fluid and electrolytes, Subject name: Medicine
[{'content': 'Hyperkalemia without ECG changes may be treated with all except - \nSelect and explain. \nA. Calcium gluconate, B. Salbutamol, C. Na bicarbonate, D. Insulin with dextrose', 'role': 'user'}, {'content': 'Answer: A \nExplanation: calcium gluconate immediately antagonises the cardiac effects of hyperkalemia, whereas the others are used to correct hyperkalemia. (reference : harrisons principles of internal medicine,19E page- 312)', 'role': 'assistant'}]