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': 'QRS complex is due to \nSelect and explain. \nA. Ventricular repolarization, B. Atrial depolarization, C. Conduction through AV node, D. Ventricular depolarization', 'role': 'user'}, {'content': 'Answer: D \nExplanation: P wave is primarily produced by atrial depolarization, the QRS complex is dominated by ventricular depolarization, and the T wave by ventricular repolarization. The U wave is an inconstant finding that may be due to ventricular myocytes with long action potentials. Ref: Ganong&;s Review of medical physiology 25th edition. Page: 522', 'role': 'assistant'}]