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': 'Treatment of Acute Hyperkalemia \nSelect and explain. \nA. Ca gluconate given, B. Insulin & Glucose reduces hyperkalemia within 4 hrs, C. Dialysis not useful, D. Resin shows the response within minutes', 'role': 'user'}, {'content': 'Answer: A \nExplanation: reference : <a href=" <p>', 'role': 'assistant'}]