This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
[{'content': 'Tall ‘T’ waves are seen in: \nSelect and explain. \nA. Hyperkalemia, B. Hypocalcemia, C. Hypercalcemia, D. Hypokalemia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Explanation: ECG changes in Hyperkalaemia Tall T waves\n(Earliest sign) Prolonged PR interval Widened QRS interval Flattened P waves Arrythmias including bradycardia,\nventricular tachycardia or fibrillation Sinus arrest or nodal rhythm with possible asystole ECG changes\nin Hypokalaemia Flattened T waves ST segment depression Prolonged QT interval Tall U waves Atrial arrythmias Ventricular tachycardia or ventricular fibrillation', 'role': 'assistant'}]