The correct answer is C. Radio buttons are used to limit user input to a single choice from a set of options.
A. Radio buttons are not used to make interfaces look better. This is the job of the visual designer.
B. Radio buttons can make coding easier, but this is not their primary purpose.
D. Radio buttons are not used to fill unique information. This is the job of text boxes or other input fields.
Radio buttons are a type of input control that allows users to select one option from a set of mutually exclusive options. They are typically used in forms to allow users to specify their preferences. For example, a form might have a set of radio buttons that allow users to select their gender, or a set of radio buttons that allow users to select their favorite color.
Radio buttons are a simple and effective way to allow users to make choices. They are easy to understand and use, and they can be used to collect a variety of different types of data.