The cells that form the top layer of the skin are:

• A. Melanocytes
• B. Fibroblasts
• C. Langerhans cells
• D. Epithelial cells

Answer: (D)

The top layer of the skin is the epidermis, a stratified squamous epithelium built mainly from epithelial cells called keratinocytes. These cells originate in the deeper layers and move upward, producing keratin as they mature, which forms the outermost protective barrier known as the stratum corneum. While melanocytes are pigment-producing cells and Langerhans cells provide immune functions within the epidermis, they do not constitute the tissue that forms the very surface. Fibroblasts reside in the dermis, supporting connective tissue, not the epidermal surface. So the cells that form the top layer are epithelial cells.