**Core Concept**
Glucose transport across cell membranes is a vital process for maintaining cellular energy homeostasis. It involves specific proteins that facilitate the movement of glucose molecules down its concentration gradient.

**Why the Correct Answer is Right**
Glucose is primarily transported through facilitated diffusion using the glucose transporter proteins (GLUTs). The most well-known GLUT is GLUT-1, which is widely distributed in various tissues, including erythrocytes, and plays a crucial role in basal glucose uptake. Another key GLUT, GLUT-4, is insulin-responsive and predominantly found in adipose tissue and skeletal muscle, enabling insulin-mediated glucose uptake in these tissues.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not specify a glucose transport mechanism. While glucose can be transported through other means, such as sodium-glucose cotransport, this is not the primary mechanism.
**Option B:** This option is incorrect as it incorrectly identifies the primary mechanism for glucose transport. While glucose can be transported through other means, such as sodium-glucose cotransport, this is not the primary mechanism.
**Option C:** This option is incorrect as it does not specify a glucose transport mechanism. While glucose can be transported through other means, such as sodium-glucose cotransport, this is not the primary mechanism.

**Clinical Pearl / High-Yield Fact**
Impaired glucose transport, particularly through GLUT-4, is a key feature of type 2 diabetes mellitus, leading to insulin resistance and hyperglycemia. This highlights the importance of understanding glucose transport mechanisms in the context of metabolic disorders.

**Correct Answer: GLUT. Glucose transport proteins (GLUTs) utilize facilitated diffusion to transport glucose across cell membranes.**