Final answer:
A colorless polish applied to the natural nail to improve adhesion is a base coat. Nails are primarily composed of a protein called keratin, important for nail strength and resilience.
Step-by-step explanation:
The colorless polish layer applied to the natural nail to improve the adhesion of polish is known as a base coat. A base coat serves as a protective layer for the nail, helps to prevent staining from colored polishes, and can help the nail polish adhere better to the nail, resulting in a longer-lasting manicure. On the other hand, a top coat is applied after the nail polish to provide a shiny finish and additional protection against chipping. Meanwhile, clear coat can generally refer to either base coats or top coats that don't have added color, and matte coat refers to a specific type of top coat that gives nails a matte finish rather than a shiny one.
Concerning the composition of nails, they are made primarily of a protein known as keratin. This fibrous protein is also found in skin and hair and is essential for the strength and resilience of the nail. Other options like elastin, collagen, and melanin serve different functions within the body and are not the main constituents of nails.The correct answer is a. Base coat.A base coat is a colorless polish layer that is applied to the natural nail to improve the adhesion of polish. It provides a smooth surface for the polish to adhere to, making it last longer. Base coats also help prevent staining of the natural nails by creating a barrier between the nail and the colored polish.