D

Oligaemic (decreased-vascularity) lung fields on CXR indicate markedly reduced pulmonary blood flow. Among the cyanotic lesions listed, Tetralogy of Fallot classically shows decreased pulmonary vascularity while the cardiac silhouette remains normal or only mildly enlarged, unlike Ebstein’s anomaly (marked cardiomegaly), pulmonary atresia (often cardiomegaly with tricuspid/right-atrial dilation), or TGA (usually plethoric lungs) [Galanski 1978, PMID 694385; Waldman 1999, PMID 10218082].