**Core Concept**
Fenestrated capillaries are a specialized type of capillary that allows for the free exchange of molecules between the bloodstream and the surrounding tissue. They are characterized by the presence of small pores or "fenestrae" in the endothelial cells lining the capillary walls, which enable the diffusion of ions, nutrients, and waste products.

**Why the Correct Answer is Right**
The presence of fenestrations in capillary endothelial cells is crucial for the functioning of certain organs and tissues that require high rates of exchange. In the kidneys, fenestrated capillaries are found in the glomeruli, where they facilitate the filtration of blood to form urine. Similarly, in the intestines, fenestrated capillaries are present in the villi, where they enable the absorption of nutrients from the gut lumen into the bloodstream. The fenestrations are usually 20-100 nanometers in diameter, allowing small molecules to pass through while restricting the passage of larger molecules, such as proteins and blood cells.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because fenestrated capillaries are not typically found in skeletal muscle tissue. Skeletal muscle is supplied by non-fenestrated capillaries that are involved in the exchange of oxygen and nutrients.

**Option B:** This option is incorrect because fenestrated capillaries are not typically found in the liver. While the liver does have a specialized sinusoidal capillary bed that facilitates exchange, it is not characterized by the presence of fenestrations.

**Option C:** This option is incorrect because fenestrated capillaries are not typically found in the skin. The skin is supplied by non-fenestrated capillaries that are involved in the exchange of oxygen and nutrients.

**Clinical Pearl / High-Yield Fact**
One key feature of fenestrated capillaries is that they are often found in organs and tissues that require high rates of exchange, such as the kidneys and intestines. This is because the presence of fenestrations allows for the efficient diffusion of molecules between the bloodstream and the surrounding tissue.

**Correct Answer:** C.