The correct answer is option 2 - Veins. Veins are blood vessels that carry deoxygenated blood from the body`s tissues back to the heart. They have one-way valves that help prevent the backward flow of blood and ensure that it flows in the right direction. Unlike arteries, which carry oxygenated blood away from the heart, veins have thinner walls and lower pressure. Veins also have a larger diameter and are able to stretch to accommodate a larger volume of blood. This allows them to carry blood from all parts of the body back to the heart, including the organs, muscles, and extremities. Options 1, 3, and 4 are not correct because arteries carry blood away from the heart, white blood cells are involved in the immune system, and platelets are involved in blood clotting.