The nurse caring for a frail 92-year-old dehydrated patient should add to the plan of care:

Choice A reason: This is incorrect because amino acids are electrolytes. Electrolytes are substances that dissociate into ions when dissolved in water and conduct electricity. Amino acids have both positive and negative charges and can form ions in solution.

Choice B reason: This is incorrect because magnesium is an electrolyte. Magnesium is a metal that forms positive ions (cations) when dissolved in water. Magnesium is important for muscle and nerve function, as well as bone health.

Choice C reason: This is incorrect because phosphates are electrolytes. Phosphates are compounds that contain the phosphate ion (PO4 3-), which is a negative ion (anion) in solution. Phosphates are involved in energy metabolism, acid-base balance, and bone formation.

Choice D reason: This is correct because glucose is a nonelectrolyte. Nonelectrolytes are substances that do not dissociate into ions when dissolved in water and do not conduct electricity. Glucose is a simple sugar that dissolves as a whole molecule in water. Glucose is the main source of energy for the body.

Choice A reason: This is incorrect because intracellular fluid is greater than extracellular fluid in a hypertonic state, not an isotonic state. A hypertonic state is when the solute concentration of the extracellular fluid is higher than the intracellular fluid, which causes water to move out of the cells and shrink them.

Choice B reason: This is incorrect because extracellular fluid is less than intracellular fluid in a hypotonic state, not an isotonic state. A hypotonic state is when the solute concentration of the extracellular fluid is lower than the intracellular fluid, which causes water to move into the cells and swell them.

Choice C reason: This is correct because intracellular and extracellular fluid is equal in an isotonic state. An isotonic state is when the solute concentration of the extracellular fluid is the same as the intracellular fluid, which causes no net movement of water across the cell membrane.

Choice D reason: This is incorrect because interstitial fluid is less than the transcellular fluid in a situation of fluid imbalance, not an isotonic state. Interstitial fluid is the fluid that surrounds the cells, while transcellular fluid is the fluid that is contained in specialized cavities, such as cerebrospinal fluid, synovial fluid, or pleural fluid. The amount of transcellular fluid is normally very small compared to the interstitial fluid, but it can increase in certain conditions, such as edema, ascites, or hydrocephalus.