In the Text command, what option allows you to automatically create a text string expression from the generated text?

The option that allows you to automatically create a text string expression from the generated text in the Text command is Reference Text. When this option is selected, it uses the actual text that you have created as a reference, which allows it to be treated as an associative entity in the design. This is particularly helpful in maintaining a connection between the visual representation of the text and the data behind it, facilitating updates and modifications.

For instance, when the underlying text is changed, the associated features built on that text can also automatically update, ensuring design consistency.

The other options do not provide this specific functionality. Using kerning spaces adjusts the space between characters but does not create a text string expression. Create Bounding Box Curves is focused on generating outlines around the text rather than making it associative. Associative indicates a relationship between objects, but in the context of this question, it is the Reference Text option that directly generates the required text string.