<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 28-year-old woman is brought to the emergency department by a friend after fainting at work and hitting her head. She is conscious, alert, and in pain as she sustained a deep laceration above her right orbit. When asked about prior fainting episodes, she says that she has had them since childhood, but she felt it was nothing serious. She also says she has frequent palpitations, shortness of breath, nausea, and, at times, chest pain and attributes this to working too hard. Her pulse is 110min, respirations are 20min, temperature is 37.4C 99.3F, and blood pressure is 11078 mm Hg. Physical examination shows tachycardia and mild hypotension. The patients electrocardiogram is obtained. Which of the following drugs is the preferable choice for first line treatment of the patients condition?? A: Calcium gluconate, B: Epinephrine, C: Flecainide, D: Magnesium sulfate, E: Procainamide,  <response>: This is a clinical vignette describing a 28-year-old woman with a history of syncope since childhood who now presents with syncope, palpitations, shortness of breath, nausea, and chest pain. She is tachycardic and mildly hypotensive. The ECG shows findings consistent with a diagnosis of long QT syndrome, which is characterized by prolonged QT intervals and risk of polymorphic ventricular tachycardia or torsades de pointes. The goal is to choose the preferable first-line treatment for this condition. Calcium gluconate, flecainide, and procainamide would not be appropriate choices in this setting. Epinephrine could potentially worsen the arrhythmia in long QT syndrome. Magnesium sulfate is the treatment of choice to stabilize cardiac membranes and shorten the prolonged QT interval in long QT syndrome.D: Magnesium sulfate 