The nurse is caring for a toddler who has a medical diagnosis of coarctation of the aorta. Which assessment finding should the nurse report to the healthcare provider immediately?

A. A pulse oximeter reading of 94% is slightly low but not an immediate emergency in a child with congenital heart disease. B. Weak femoral pulses are a classic finding in coarctation of the aorta and are expected, not an urgent change to report unless newly developed. C. Crackles at the end of inspiration are abnormal and may indicate left-sided heart failure or pulmonary congestion, which can quickly become life-threatening in a child with coarctation of the aorta. This requires immediate reporting and intervention. D. Higher blood pressure in the upper extremities compared to the lower extremities is expected with this condition and not an acute concern.