What is the primary function of a foot file?

The primary function of a foot file is to smooth calluses, making option A the correct choice. Calluses often develop on the feet due to repeated friction or pressure, and a foot file is specifically designed to effectively remove and smooth these rough patches of skin. The tool helps to improve the overall look and feel of the feet, making them more comfortable and aesthetically pleasing.

The other options, while related to foot care, do not accurately represent the primary use of a foot file. Shaping toenails is typically accomplished with nail clippers or files specifically designed for nails, rather than a foot file. Removing nail polish is done with a cotton ball or pad and nail polish remover, which is unrelated to the function of a foot file. Exfoliating skin, although it involves removing dead skin cells, is more broadly associated with products like scrubs or professional exfoliation treatments, rather than specifically with a foot file's main purpose. Thus, the focus of a foot file remains on smoothing calluses effectively.