In what scenario is the "After field sourcing" trigger used?

The "After field sourcing" trigger is specifically used in scenarios where a field's options are being dynamically loaded based on user input. This occurs often in forms where the selection of one field can affect the available options in another field, such as selecting a category that then filters the choices available in a subsequent sub-category field.

By using the "After field sourcing" trigger, the system can execute certain actions or scripts right after these field options are sourced but before the user has made a selection. This is critical for ensuring that the user interface responds correctly to user actions and loads relevant options right away, providing a seamless experience without requiring extra saves or validations.

Recognizing this, other options do not fit the context of this specific trigger. For instance, saving a record or validating data are not instances where field sourcing is directly involved. Similarly, fetching data from an external source doesn't pertain to field sourcing that is triggered by user input on the record itself. Thus, the scenario where the options of a field are loaded based on user input is the correct and appropriate application of the "After field sourcing" trigger.