Final answer:
Intravenous therapy can serve multiple functions including delivering drugs, providing nutrition, and preventing dehydration. For dehydrated patients, an isotonic saline solution is typically administered to maintain proper electrolyte balance and osmotic pressure.
Step-by-step explanation:
Intravenous therapy is used for a variety of clinical purposes such as to give drugs or blood, provide nutrition, and prevent dehydration, making 'D. All of the above' the correct answer to the question. When a dehydrated human patient requires fluids intravenously, they are often given saline at a concentration that is isotonic with respect to body fluids. This isotonic saline solution encompasses ordinary NaCl solution or a mixture with Na lactate as needed. It is crucial for the solutions to be isotonic to maintain the proper osmotic pressure and electrolyte balance within the patient's body, and to prevent adverse effects that can occur if water enters or leaves the body's cells too rapidly.