Which of the following describes a cyanotic congenital heart abnormality?

Cyanotic congenital heart defects are characterized by a right-to-left shunt, leading to a lower oxygen saturation in the blood, resulting in cyanosis (a bluish discoloration of the skin due to inadequate oxygenation). Transposition of the great vessels is a prime example of such an abnormality. In this condition, the aorta arises from the right ventricle and the pulmonary artery arises from the left ventricle, causing systemic and pulmonary circulation to run in parallel rather than in series. This results in deoxygenated blood circulating through the body, leading to significant hypoxemia and cyanosis in affected neonates.

The other options listed are predominantly acyanotic defects, where oxygen-rich and oxygen-poor blood mixes less significantly, typically resulting in a more favorable oxygenation status. Aortic stenosis narrows the aorta, affecting blood flow but not typically causing cyanosis. Ventricular septal defect and atrial septal defect involve openings that allow blood to flow between heart chambers, promoting mixing of oxygenated and deoxygenated blood but generally do not lead to cyanosis unless they are very large or associated with additional heart defects.