**Core Concept**
Class I MHC (Major Histocompatibility Complex) molecules are a group of glycoproteins expressed on the surface of almost all nucleated cells in the body. They play a crucial role in the immune system by presenting peptide fragments from proteins inside the cell to T-cells, helping to trigger an immune response.

**Why the Correct Answer is Right**
Class I MHC molecules are expressed on the surface of almost all nucleated cells, including epithelial cells, endothelial cells, and immune cells like B cells, T cells, and macrophages. This broad expression allows the immune system to monitor the body's cells for signs of infection or cancer. The peptide fragments presented by Class I MHC molecules are typically derived from proteins synthesized within the cell.

**Why Each Wrong Option is Incorrect**
* **Option A:** This choice is not provided, so we cannot evaluate it.
* **Option B:** This choice is not provided, so we cannot evaluate it.
* **Option C:** This choice is not provided, so we cannot evaluate it.
* **Option D:** This choice is not provided, so we cannot evaluate it.

**Clinical Pearl / High-Yield Fact**
One important exception to the broad expression of Class I MHC molecules is the central nervous system (CNS), where these molecules are not typically expressed on the surface of neurons or glial cells. This relative lack of MHC expression is thought to help protect the CNS from autoimmune responses.

**Correct Answer: **