In the Text command, which one of these cannot be used as a Font Style?

In the context of the Text command within Siemens NX, the font styles primarily include Regular, Bold, and Italic. Each of these is a standard way to modify text appearance to enhance visibility or emphasize certain parts of the text. Regular is the default text style, while Bold adds weight to the characters, and Italic slants the text for emphasis.

Underlined, however, is not considered a font style in the same sense as the others. Instead, it is a text decoration that is often used to provide emphasis or distinguish text but does not fundamentally change the font style itself. Therefore, underlined doesn't fit into the category of font styles that can be applied directly within the Text command in the same way as Regular, Bold, or Italic do. This distinction highlights why underlined is the correct choice for what cannot be classified as a font style in this context.