<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 21-year-old woman presents with palpitations and anxiety. She had a recent outpatient ECG that was suggestive of supraventricular tachycardia, but her previous physician failed to find any underlying disease. No other significant past medical history. Her vital signs include blood pressure 10265 mm Hg, pulse 120min, respiratory rate 17min, and temperature 36.5C 97.7F. Electrophysiological studies reveal an atrioventricular nodal reentrant tachycardia. The patient refuses an ablation procedure so it is decided to perform synchronized cardioversion with consequent ongoing management with verapamil. Which of the following ECG features should be monitored in this patient during treatment?? A: QRS complex amplitude, B: Length of QT interval, C: Length of PR interval, D: Length of QRS complex, E: Amplitude and direction of the T wave,  <response>: This is a question about ECG monitoring in a patient with supraventricular tachycardia SVT who is being treated with synchronized cardioversion and verapamil. The key points are:- 21 year old woman with palpitations, anxiety, and SVT confirmed on EP study- Treatment plan is synchronized cardioversion followed by verapamil - Question asks which ECG feature should be monitored during treatmentTo answer this, we need to consider the ECG changes that may occur with SVT and the effects of cardioversion and verapamil. SVT usually shows a narrow QRS complex unless there is aberrant conduction. Verapamil is a calcium channel blocker that slows AV nodal conduction to help control the tachycardia. Cardioversion synchronizes shock delivery with the QRS complex to avoid inducing ventricular fibrillation. The PR interval and QRS duration reflect AV nodal conduction and ventricular depolarization respectively. Monitoring these intervals makes sense to assess verapamils effects on slowing AV conduction. The QT interval, T wave changes, and QRS amplitude are less relevant to follow in this clinical scenario.C: Length of PR interval 