Causes of cynosls-: (A) TOF, (B) PDA, (C) Tricuspid atresia, (D) Eisonmenger's complex
Answer is A. Tetralogy of Fallot causes low oxygen levels in the blood. This leads to cyanosis (a bluish-purple color to the skin). The classic form includes four defects of the hea and its major blood vessels: Ventricular septal defect (hole between the right and left ventricles) Ref Davidson 23rd edition pg 455