Which statement best describes isotonic, hypotonic, and hypertonic intravenous fluids, with one example each and where they act in body compartments?

• A. Isotonic fluids like 0.9% NS stay in extracellular space; hypotonic fluids like 0.45% NS move into cells; hypertonic fluids like 3% NS draw water out of cells into extracellular space
• B. Isotonic fluids like Lactated Ringers move into cells; hypotonic fluids like 0.9% NS stay in vascular space; hypertonic fluids like 5% dextrose move into cells
• C. Isotonic fluids like 5% dextrose remain in cells; hypotonic fluids like 3% NS remain in extracellular space; hypertonic fluids like 0.9% NS pull water into cells
• D. Isotonic fluids like 0.45% NS move water out of cells; hypotonic fluids like 3% NS draw water from extracellular; hypertonic fluids like 0.9% NS stay in cells

Answer: (A)