Surgical closure of the ductus arteriosus would result in which of the following?

A. Prevent the return of oxygenated blood to the lungs is incorrect because closing the ductus arteriosus does not block pulmonary venous return. Blood still returns from the lungs to the left atrium and ventricle normally. B. Decrease the edema in the legs and feet is incorrect because peripheral edema is not directly related to a patent ductus arteriosus (PDA). Edema is more associated with congestive heart failure or systemic venous congestion, which may be secondary but is not the immediate effect of surgical closure. C. Stop the loss of unoxygenated blood to the systemic circulation is partially correct in theory, as a PDA can allow blood to shunt from the aorta to the pulmonary artery, but the key concern is left-to-right shunting of oxygenated blood back to the lungs, not unoxygenated blood going systemically. D. Increase the oxygenation of blood is correct because surgical closure of a PDA eliminates the abnormal shunt that allows oxygenated blood from the aorta to flow back into the pulmonary circulation. This reduces pulmonary overcirculation and ensures that oxygenated blood remains in the systemic circulation, improving overall tissue oxygenation.