Correct option is C
A rough file is characterized by large, widely spaced teeth, designed for rapid removal of material. It is typically used in the initial stages of filing when a large amount of material needs to be removed quickly. Among the given figures, the one showing the coarsest tooth pattern corresponds to the rough file. Finer files, such as smooth or second-cut files, have closely spaced teeth and are used for finishing operations. Therefore, identifying the rough file depends on recognizing the largest tooth spacing.
