**Core Concept**
Glucose transporters are proteins responsible for facilitating the uptake of glucose into cells. During fasting, the body adapts by altering the expression and activity of these transporters to manage glucose levels. This adaptation is crucial for maintaining energy homeostasis.

**Why the Correct Answer is Right**
When an individual fasts overnight, the body's demand for glucose decreases, and insulin levels are low. As a result, the expression of glucose transporter 4 (GLUT4) in adipocytes (fat cells) is reduced. GLUT4 is the primary glucose transporter in adipocytes and plays a key role in glucose uptake in these cells. With lower GLUT4 expression, glucose uptake in adipocytes is decreased, which helps to conserve glucose for other tissues that require it.

**Why Each Wrong Option is Incorrect**
**Option A:** Brain cells continuously require glucose for energy, even during fasting. The expression of glucose transporters in brain cells is not reduced during fasting, as glucose is essential for maintaining brain function.

**Option B:** Red Blood Cells (RBCs) rely on glucose for energy and do not require insulin for glucose uptake. The glucose transporter in RBCs, GLUT1, is constitutively active and not regulated by insulin or fasting.

**Option D:** Hepatocytes (liver cells) can utilize alternative energy sources, such as ketone bodies, during fasting. The expression of glucose transporters in hepatocytes is not significantly reduced during fasting, as the liver continues to play a critical role in glucose homeostasis.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the regulation of glucose transporters is a key adaptation mechanism in response to changes in glucose availability. Understanding this concept is crucial for managing glucose metabolism disorders, such as type 2 diabetes.

**✓ Correct Answer: C. Adipocyte Adipocytes exhibit reduced glucose transporter expression after overnight fasting.**