Which artery carries oxygen-poor blood from the heart to the lungs?

The pulmonary artery is the correct answer because it is specifically responsible for transporting oxygen-poor blood from the right side of the heart to the lungs. In the lungs, this blood undergoes a crucial process where it receives oxygen and releases carbon dioxide, thus becoming oxygen-rich before returning to the heart via the pulmonary veins.

In contrast, the aorta carries oxygen-rich blood from the heart to the rest of the body, making it essential for supplying oxygen to tissues. The carotid artery, which supplies blood to the brain, and the femoral artery, supplying blood to the lower limbs, also carry oxygen-rich blood rather than oxygen-poor blood. Thus, the pulmonary artery plays a unique role in the circulatory system, where it is integral for the process of oxygenation in the lungs.