What is the function of a silica nail buffer?

The function of a silica nail buffer is to smooth and shine the nail surface, which is why the choice indicating this function is correct. Silica nail buffers contain fine particles of silica, which are effective in creating a polished appearance on the nails. When used properly, a silica buffer can gently abrade the nail surface, helping to remove any irregularities and enhance its shine, giving the nails a well-groomed and healthy look.

Other options refer to different aspects of nail care. Adding color to the nails pertains to nail polish application rather than the function of a buffer. Removing nail polish is achieved through the use of solvents, typically acetone or non-acetone removers, and does not involve the use of a buffer at all. Strengthening natural nails is more commonly associated with treatments or products designed to reinforce the nail structure, such as base coats or nail strengthening formulas, which is also outside the scope of what a buffer does. Thus, the correct choice accurately encapsulates the primary purpose of a silica nail buffer.