Aveoli are the small sacks in the lungs, where gases such as oxygen and carbon dioxide are transferred into/out of the blood stream. Blood would be the answer, as blood is not transferred through alveoli; it stays in blood vessels and is oxygenated at the alveoli.
I might die in this situation, but i would probably pick C
<span>the ratio of the force produced by a machine to the force applied to it, used in assessing the performance of a machine.</span>