Final answer:
True, the closure of the pulmonary valve would prevent deoxygenated blood from reaching the lungs, thus stopping the oxygenated blood from returning to the lungs.
Step-by-step explanation:
The statement that surgical closure of a part of the heart would prevent the return of oxygenated blood to the lungs is true. Specifically, this is referring to the pulmonary veins, which carry oxygenated blood from the lungs back to the heart. When the pulmonary valve is surgically closed, which normally allows blood to flow from the right ventricle into the pulmonary artery, it would impede the deoxygenated blood from reaching the lungs to be oxygenated. Therefore, the pulmonary veins would be unable to return oxygenated blood to the lungs because it would not be oxygenated in the first place due to the surgical closure.