<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:Several hours after vaginal delivery, a male newborn delivered at full-term develops tachycardia and tachypnea. His blood pressure is within normal limits. Pulse oximetry on room air shows an oxygen saturation of 79 in the right hand and 61 in the left foot. Physical examination shows bluish discoloration of the face and trunk, supraclavicular and intercostal retractions, and a machine-like murmur over the precordium. Bedside echocardiography shows pulmonary and systemic circulation are in parallel rather than in series. What is the most appropriate pharmacotherapy for this patient?? A: Sildenafil, B: Alprostadil, C: Metoprolol, D: Indomethacin, E: Dopamine,  <response>: This is a question about a newborn with signs and symptoms consistent with a diagnosis of persistent pulmonary hypertension of the newborn PPHN. The key findings are tachycardia, tachypnea, hypoxemia that is worse in the lower extremities right-to-left shunting, respiratory distress, and echocardiographic evidence of parallel circulation rather than the normal in-series circulation. PPHN is caused by failure of normal pulmonary vascular relaxation at birth leading to pulmonary hypertension. The goal of therapy is to reduce pulmonary vascular resistance.B: Alprostadil 