Which of the following definitions matches the term 'hypertonic?

A. Administration of a small volume of intravenous solution, connected to and hung higher than a primary intravenous solution is incorrect because this describes a secondary IV (or piggyback) infusion, not a hypertonic solution. It refers to the method of delivery rather than the solution’s osmolarity. B. Solution that has the same concentration of solutes as human blood is incorrect because this defines an isotonic solution, not a hypertonic one. Isotonic solutions, such as 0.9% sodium chloride, neither pull fluid into nor out of cells significantly, maintaining fluid balance. C. Intravenous solutions are less concentrated than blood and other body fluids. These solutions are used to treat a fluid and electrolyte imbalance by moving water into the cells is incorrect because this describes hypotonic solutions. Hypotonic fluids, such as 0.45% sodium chloride, shift water into the cells, which is the opposite effect of hypertonic solutions. D. Intravenous solutions are more concentrated than body fluids. They pull fluid from the interstitial spaces and cells into the veins is correct because hypertonic solutions have a higher solute concentration than plasma. Examples include 3% sodium chloride or 10% dextrose in water. These solutions draw water out of cells and interstitial spaces into the vascular compartment, making them useful for treating severe hyponatremia or cerebral edema, but they must be administered carefully to avoid fluid overload or cellular dehydration.