Hierarchy - I don’t think I have the full context of the question but the word fits the best of its biology related
The correct answer is high, low.
Arteries are part of the circulatory system and are responsible for carrying blood away from the heart and around the body. The arterial blood is oxygenated and this process ensures that every tissue around the body will receive oxygen and nutrients through this blood flow.
Veins are also part of the circulatory system and are responsible for carrying the deoxygenated blood from the tissues back to the heart.
Venous pressure is much lower than the arterial pressure. More specifically, venous pressure ranges from 5 to 8 mmHg, while arterial pressure ranges from 15 to 30 mmHg.
What about transport you might ask well
in plants, how does a Redwood, one of the tallest trees in the world, move water from the soil to the needles on its tallest branches over 300 ft in the air? (That’s over 30 stories high!) Or how does a carrot transport the sugars made in its green, leafy tops below the surface of the soil to grow a sweet, orange taproot? Well, certain types of plants (vascular plants) have a system for transporting water, minerals, and nutrients (food!) throughout their bodies; it’s called the vascular system. Think of it as the plant’s plumbing, which is made up of cells that are stacked on top of one another to form long tubes from the tip of the root to the top of the plant. To learn more about it, let’s study the stem.
Answer:
If you're on EDGE 2021, it's NOT D.
I think it's A.
A group of organ systems working together is an organism.