This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Physiology
[{'content': "ECG change seen in Hypokalemia \nSelect and explain. \nA. Tall 'T' wave, B. U wave, C. Sine wave configration, D. Shoening of QT interval", 'role': 'user'}, {'content': "Answer: B \nExplanation: Hypokalemia (plasma K+ +-3.5 meq/L). PR interval = 0.2 s; QRS interval = 0.06 s; ST-segment depression. A prominent U wave is now present immediately following the T. Tall T wave is present in hyperkalemiaIf the U wave is erroneously considered a pa of the T, a falsely prolonged QT interval of 0.6 s will be measured in hypokalemia but true QT interval remain same in severe hypokalemia (plasma K+ +-2.5 meq/L)Ref: 23rd Edition of Ganong's Review of Medical Physiology pg no:503", 'role': 'assistant'}]