This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: ECG and Arrhythmia 2, Subject name: Medicine
[{'content': 'A 12-year old child with renal tubular acidosis type I is having muscle cramps and weakness. ECG shows all except: \nSelect and explain. \nA. T wave inversion with U waves, B. ST depression, C. Hea rate of 75 beats per minute, D. Absent P waves', 'role': 'user'}, {'content': 'Answer: D \nExplanation: ECG findings with h/o renal tubular acidosis with c/o muscle cramps and weakness s/o Hypokalemia Hypokalemia ECG Increased width of the P waves Prolongation of the PR interval T wave flattening and inversion ST depression Prominent U waves Long QT interval due to fusion of the T and U wave = long QU interval', 'role': 'assistant'}]