Final answer:
The only veins that carry oxygenated blood to the heart are the pulmonary veins.
Step-by-step explanation:
The only veins that carry oxygenated blood to the heart are the pulmonary veins. These veins transport highly oxygenated blood from the lungs to the heart. The pulmonary veins then conduct the oxygenated blood into the left atrium, which pumps it into the left ventricle, and from there, it is pumped into the aorta and distributed to the rest of the body.