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': 'Which of the following represents ventricular depolarization on ECG? \nSelect and explain. \nA. PQ, B. PR, C. QRS, D. ST', 'role': 'user'}, {'content': 'Answer: C \nExplanation: P wave which represents atrial depolarization.\nThe QRS complex represents ventricular depolarization and the\xa0ST-T-U complex (ST segment,\xa0T wave,\xa0and U wave) represents ventricular repolarization.\nThe J point is the junction between the end of the QRS complex and the beginning of the ST segment.\nAtrial repolarization (ST and T) is usually too low in amplitude to be detected, but it may become apparent in conditions such as acute pericarditis and atrial infarction.', 'role': 'assistant'}]