Gaseous atoms and plasmic ions expand in all directions.
Well, right away I know that it is some sort of mutualistic relationship. Since this is not an option here, my best guesses are either <em>B or C.</em>
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Please let me know if I was right :)
Answer: Hemoglobin
Explanation: Hemoglobin is a protein very rich in iron found in red blood cells and is responsible for the transportation of Oxygen from the lungs to the whole body. Oxygen binds to the hemoglobin in red blood cells and the red pigmentation of blood that is highly oxygenated is due to the hemoglobin content found in RBC's.
A - The alveoli have a membrane that is only one cell thick to allow for a short diffusion time to capillaries.