**Core Concept**
Dextrose is a form of glucose, a simple sugar that serves as a primary source of energy for cells. It is commonly administered intravenously or orally to treat hypoglycemia, a condition characterized by abnormally low blood glucose levels.

**Why the Correct Answer is Right**
Dextrose solutions, typically 50% dextrose in water, are used to rapidly elevate blood glucose levels in patients with hypoglycemia. When administered intravenously, dextrose is rapidly absorbed into the bloodstream and can increase blood glucose levels within minutes. This is because the glucose molecule is easily absorbed by cells, particularly the liver and muscles, which can then metabolize it to produce energy.

**Why Each Wrong Option is Incorrect**
**Option A:**
This option is incorrect because it does not accurately describe the primary function of dextrose.

**Option B:**
This option is incorrect because it does not specify the type of sugar being referred to. While fructose is a type of sugar, it is not the same as dextrose.

**Option C:**
This option is incorrect because it does not accurately describe the primary use of dextrose.

**Clinical Pearl / High-Yield Fact**
When administering dextrose solutions, it is essential to monitor the patient's blood glucose levels closely to avoid hyperglycemia, a condition characterized by abnormally high blood glucose levels. This can be particularly problematic for patients with diabetes or those who are at risk of developing diabetic ketoacidosis.

**Correct Answer: D. Glucose.