B. Bicarbonate
<em>The blood brings bicarbonate to the lungs, and then it is exhaled as carbon dioxide. The kidneys also help regulate bicarbonate... it is excreted and reabsorbed by the kidneys.</em>
<em>The body's main response is to get rid of more carbonic acid and hold on to as much bicarbonate base in the kidneys as it can.</em>
The answer is tissue fluid. Tissue fluid holds far smaller quantity of protein molecules because they are too large to escape easily over the tiny holes in the capillary endothelium. Tissue fluid doesn't contain red blood cells because they are too large, but does comprise some white blood cells.
C. The Composition of your blood
