The nurse assessing a premature newborn infant auscultates a continuous machinery-like murmur. This finding is associated with which congenital heart defect?

A. Pulmonary stenosis: Pulmonary stenosis typically produces a systolic ejection murmur heard best at the upper left sternal border. The murmur is not continuous and does not have the classic machinery-like quality associated with PDA. B. Patent ductus arteriosus: Patent ductus arteriosus (PDA) allows blood to flow from the aorta to the pulmonary artery, creating a continuous “machinery-like” murmur that is heard throughout systole and diastole. This distinctive murmur is most prominent at the left upper sternal border and is characteristic of PDA, particularly in premature infants. C. Ventricular septal defect: A ventricular septal defect usually produces a harsh, holosystolic murmur at the lower left sternal border. The murmur is confined to systole and lacks the continuous, machinery-like quality of PDA. D. Coarctation of the aorta: Coarctation of the aorta often presents with systolic murmurs, diminished femoral pulses, and differential blood pressures between upper and lower extremities. The murmur is not continuous and does not produce the machinery-like sound seen in PDA.