Final answer:
The ductus venosus carries oxygen-rich blood from the umbilical vein to the inferior vena cava in the fetal circulation. Therefore, the correct option is D.
Step-by-step explanation:
The structure that carries oxygenated blood from the umbilical vein to the inferior vena cava (IVC) is the ductus venosus. The ductus venosus is a temporary blood vessel in the fetus that allows much of the freshly oxygenated blood from the placenta to bypass the fetal liver and flow directly to the fetal heart, facilitating efficient circulation before birth. Once the baby is born and starts to breathe on its own, this vessel gradually closes and becomes the ligamentum venosum.