You are incorrect - the most likely etiology of our patient's pulmonary hypertension is idiopathic pulmonary arterial hypertension.
Your choice: Ventricular septal defect
Patients with a ventricular septal defect may develop pulmonary hypertension. Physical findings include a harsh systolic murmur at an early age. Pulmonary hypertension causes a reversal of the shunt and leads to cyanosis and clubbing.