What is an input mask primarily used for?

An input mask is primarily used to control how data is entered in a specific format. It creates a template that guides users in entering data in a consistent way, which minimizes errors and ensures uniformity. This is important in scenarios where the format of the data is crucial, such as phone numbers, social security numbers, or dates. By using an input mask, restrictions can be applied so that users adhere to the required input format, thereby enhancing data quality and making it easier to validate or process the data later.

Other options may touch on aspects related to data entry but do not directly capture the primary function of an input mask. Visualizing data entry patterns and enhancing the appearance of data forms pertain more to the user interface and user experience rather than controlling the input format. Forcing a verification check on input data is about validating data after it has been entered, rather than dictating how that data should be entered in the first place. Thus, option B succinctly captures the core purpose of an input mask in data entry scenarios.