Which option is NOT possible when using the Combo Box widget?

The reasoning behind the choice that indicates it is not possible to use the Special List section for entity alternatives lies in the specific functionality of the Combo Box widget. The Combo Box allows developers to specify alternatives through a variety of means, one of which includes the ability to pull from source entities or record lists that contain dynamic data.

Using the Source Entity property and the Source Record List property is a common practice, as they provide the capability to populate the Combo Box with data that is representative of those entities or records, thereby allowing for dynamic content based on the underlying data structure.

Static lists for alternatives can also be utilized within a Combo Box, which is valuable for scenarios where the list of options does not change and is predefined, offering a quick way to present fixed options to users.

However, the Special List section serves a different purpose and is not intended for using entity alternatives. It is mainly utilized for predefined sets of options that have specific meanings or usage cases within the application framework and cannot integrate with dynamic data sources in the way that entity alternatives can. This distinction is vital for understanding how to effectively utilize the Combo Box widget within OutSystems.