A nurse is caring for an infant diagnosed with tetralogy of Fallot. The infant's caregiver asks the nurse to explain this diagnosis. Which of the following is an accurate statement about this condition?

Rationale: A. “Tetralogy of Fallot is a group of three heart defects…”: This lists three defects rather than four and identifies conditions that are not part of Tetralogy of Fallot. Mislabeling defects such as aortic stenosis and atrial septal defect can lead to misunderstanding of the infant’s cardiac physiology and the expected clinical manifestations. B. "…due to the lack of a functional tricuspid valve.": This describes tricuspid atresia, a different congenital heart defect in which blood flow from the right atrium to the right ventricle is blocked. The pathophysiology and oxygenation patterns differ significantly from Tetralogy of Fallot. C. “Tetralogy of Fallot is a group of four heart defects…”: Tetralogy of Fallot consists of pulmonary stenosis, ventricular septal defect, right ventricular hypertrophy, and an overriding aorta. These defects collectively reduce pulmonary blood flow and increase mixing of oxygenated and deoxygenated blood, explaining symptoms such as cyanosis and hypoxic spells. D. “…due to a single artery leaving the ventricles…”: This explanation describes truncus arteriosus, a congenital heart defect where one arterial trunk supplies systemic, pulmonary, and coronary circulation. Although mixing of blood also occurs in that condition, it is not the mechanism involved in Tetralogy of Fallot.