The blood cells likely placed in a "hypotonic solution".
<u>Option: A</u>
<u>Explanation:</u>
When human blood cells are immersed in a solution with a low concentration of solute than is present in cells, osmosis allows water to pass through the cells, allowing the cells to get swollen; such a fluid is hypotonic to the cells. But when held in a solution with a greater concentration of solute, osmosis allows water to pass out of the cell, the cell is smaller and crenated in form; then a solution is hypertonic to the cells.
Healthcare facilities preserve human blood cells in a plasma solution that has the proper salt and protein ratios. Such solution is formulated to be mildly hypertonic to the red cells, thus maintaining the integrity of the cells and avoiding hemolysis.
