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': 'The ECG change seen in hyperkalemia is \nSelect and explain. \nA. Narrowing of the QRS complex, B. Increased amplitude of P waves, C. Narrowing and peaking of T waves, D. Ventricular arrhythmias', 'role': 'user'}, {'content': "Answer: A \nExplanation: Hyperkalemia (plasma K+ +-7.0 meq/L). The PR and QRS intervals are within normal limits. Very tall, slender peaked T waves are now present. Hyperkalemia (plasma K+ +-8.5 meq/L). The QRS complex is broad and slurred and the QRS interval has widened to 0.2 s. The T waves remain tall and slender Fuher elevation of the plasma K+ level may result in ventricular tachycardia and ventricular fibrillation. Ref: Ganong's Review of Medical Physiology Twenty-Third Edition Page No: 504", 'role': 'assistant'}]