Final answer:
The systemic arteries contain blood with the lowest oxygen content among the given options.
Step-by-step explanation:
The correct answer is d) Systemic arteries.
The systemic arteries contain blood with the lowest oxygen content among the given options. The systemic circuit is responsible for delivering oxygenated blood to the body's organs and tissues. Blood that has already been oxygenated by the lungs is pumped from the left ventricle into the aorta, which is the largest artery in the body. The aorta and its branches, the systemic arteries, distribute this oxygen-rich blood to the rest of the body.