Which of the following statements best describes the primary function of Major Histocompatibility Complex (MHC) class I molecules?

✓ Correct Answer: Option B

MHC class I molecules are expressed on nearly all nucleated cells and present endogenous (intracellular) antigens, such as viral peptides or tumor antigens, to CD8+ cytotoxic T lymphocytes (CTLs), signaling infected or abnormal cells for destruction.