What is the primary function of veins?

The primary function of veins is to carry blood towards the heart. Veins are blood vessels that transport deoxygenated blood from the body back to the heart, where the blood then gets reoxygenated in the lungs before being pumped out again. This process is crucial for maintaining proper circulation and ensuring that the body's tissues receive the oxygen they need and that carbon dioxide and other waste products are transported for removal.

In contrast, arteries are the vessels responsible for carrying blood away from the heart, typically rich in oxygen, to supply the body's organs and tissues. The roles of veins and arteries differ distinctly in the circulatory system, highlighting the importance of each type of vessel for overall cardiovascular function. The options addressing the distribution of oxygen-rich blood or the absorption of nutrients pertain to different physiological processes and do not accurately describe the specific role of veins.