Answer:Capillaries
Explanation: Capillaries are tiny, thin walled vessels that form a network to take blood through the organs and other body tissues. The dense networks of capillaries present a large surface area, which allows materials to be exchanged between body cells and the blood rapidly.
<span>The appropriate justification of this is that B. As hydrilla is aquatic in nature, the roots do not have to search for minerals, and there is no need for xylem to absorb nutrients because the plant is surrounded by water that has dissolved nutrients in it. </span>
The correct answer is the lungs. Usually, in the systemic organs such as the liver, kidneys, and the heart; hypoxia or low oxygen levels cause the blood vessels supplying them to vasodilate to increase flow of blood and prevent ischemia. Adequate oxygenation of systemic organs cause the blood supply to vasoconstrict to prevent pooling of oxygenated blood and shunt it to other organs that need the oxygen more.
However, in the lungs, the opposite is true because in the setting of hypoxia, the blood vessels of the lungs vasoconstrict as to shunt the blood to other parts of the lungs with adequate oxygenation for the blood to be adequately oxygenated. If there is adequate oxygen in the lungs, then blood vessels vasodilate to efficiently get the oxygen from the lungs.
The oxygen-poor blood enters the heart from the body through the SVC, or, the superior vena cava. The oxygen-poor blood then enters the right atrium (RA) of the heart.