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': 'Prominent U waves on the ECG is a feature of - \nSelect and explain. \nA. Hyponatremia, B. Hypernatremia, C. Hypokalemia, D. Hyperkalemia', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Electrocardiographic changes in hypokalemia include broad flat T waves, ST depression, u wave and QT prolongation. (reference: harrisons principles of internal medicine,19E page-307)', 'role': 'assistant'}]