Which of the following vessels directly collects blood from the body's tissues?

The correct choice is the vena cava because it is responsible for collecting deoxygenated blood from the body's tissues and returning it to the heart. The vena cava consists of two main parts: the superior vena cava, which drains blood from the upper part of the body, and the inferior vena cava, which drains blood from the lower body. Once the blood circulates through the capillaries and delivers oxygen and nutrients to the tissues, it must return to the heart to be oxygenated again. The vena cava plays a crucial role in this process by collecting and transporting that blood back to the right atrium of the heart.

The aorta, arteries, and capillaries serve different roles in the circulatory system. The aorta is the main artery that carries oxygenated blood away from the heart to the rest of the body. Arteries carry blood away from the heart, branching out into smaller arterioles and ultimately leading to capillaries, where gas exchange occurs. Capillaries facilitate the exchange of gases, nutrients, and waste products between blood and tissues, but they do not collect blood; instead, they transition blood flow from arteries to veins.