How is the nail structure primarily composed?

The correct choice highlights the primary components of nail structure, which consists of the nail plate, nail bed, cuticle, and matrix.

The nail plate is the visible part of the nail and is made primarily of a tough protein called keratin, which provides strength and durability. The nail bed is the area of skin beneath the nail plate that supports it. The cuticle serves as a protective barrier that prevents pathogens from entering the nail matrix, which is the area where nail growth occurs.

Understanding these components is crucial for effective nail care and treatment in cosmetology. The other options present items or materials associated with nails, such as polish, tools like files and buffers, or artificial enhancements like tips and adhesives, which are not intrinsic parts of the nail structure itself.