Which artery is responsible for carrying unoxygenated blood away from the heart?

The pulmonary artery is the correct answer because it is specifically responsible for carrying unoxygenated blood from the heart to the lungs. In the circulatory system, after deoxygenated blood returns to the right atrium of the heart, it moves into the right ventricle, which then pumps it into the pulmonary arteries. These arteries transport the blood to the lungs where carbon dioxide is exchanged for oxygen. This critical function is distinct from other arteries, which typically carry oxygenated blood.

Other arteries listed in the options serve different roles. For instance, the coronary arteriole is involved in supplying blood to the heart muscle itself and primarily carries oxygenated blood. The hepatic artery supplies oxygenated blood to the liver, and the aorta is the main artery that carries oxygenated blood away from the heart to the rest of the body. Hence, in the context of unoxygenated blood transport, the pulmonary artery is the artery that fits this description accurately.