A 3-week-old premature infant is evaluated for poor weight gain and increased work of breathing. The infant has had 2 episodes of lower respiratory tract infection requiring hospitalization since birth. Temperature is 37.0°C (98.6°F), heart rate is 158/min, respiratory rate is 52/min, and blood pressure is 78/38 mm Hg. Physical examination shows bounding peripheral pulses and a widened pulse pressure. Cardiac auscultation reveals a continuous, “machine-like” murmur with a crescendo that peaks around S2, best heard at the left infraclavicular area. Which of the following is the most likely underlying lesion?