Which of the following best describes electroplating?

Electroplating is best described as coating a substrate with metal via electrolysis. This process involves using an electric current to reduce cations of metal from a solution and deposit them onto a conductive surface, creating a layer of metal. The application of electrical current facilitates the movement of metal ions toward the substrate, where they gain electrons and form a solid layer. This technique is widely used for enhancing the appearance, corrosion resistance, and conductivity of materials.

The other options, while related to material manipulation, do not accurately capture the process of electroplating. For instance, removing layers of metal from a surface pertains to processes like etching or sanding, which are not part of electroplating's purpose or method. Similarly, creating a protective layer of paint involves a completely different chemical approach and does not involve the use of electric current to deposit metal. Lastly, applying heat to fuse metal components describes welding or brazing, which is a distinctly different process that does not involve the electrochemical reactions characteristic of electroplating.