I feel the producers are the most important, because if they collapse, soon the plant eaters will collapse, then the animals that eat them, and so on.
You could also say A scavenger is the most imporant because without them we wouldnt be ŕecycling´ food.
Its B because Arteries deliver oxygenated blood to the capillaries, where the exchange of oxygen and carbon dioxide takes place.<span>
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