What is the structure of the inferior vena cava

Structure. The IVC is formed by the joining of the left and right common iliac veins and brings collected blood into the right atrium of the heart. It also joins with the azygos vein (which runs on the right side of the vertebral column) and venous plexuses next to the spinal cord.

Source: common iliac vein; lumbar veins;

i think that the best answer would be c.

tell me if im wrong : )