To exit a screen with mandatory fields unfilled by using the Cancel button, what must be done?

The correct answer highlights the proper approach to handle a Cancel button in the context of SAP screens. When you assign function type E to the Cancel button, it indicates that the button is intended to perform an exit operation in the program. This is essential because the function type E allows for the handling of exit commands properly, ensuring that any necessary clean-up or confirmation processes can be executed when a user attempts to leave the screen without filling in mandatory fields.

By handling this in a module with the addition AT EXIT-COMMAND, the program can effectively manage the user experience by providing validation or confirmation prompts if there are mandatory fields that have not been completed. This approach ensures that users are appropriately warned before leaving the screen and that the application logic maintains data integrity by preventing users from inadvertently exiting without completing necessary inputs.

Other options do not align with the standard practice of handling Cancel operations in SAP applications. For instance, setting the function code to CANCEL is less straightforward in terms of achieving the desired exit behavior when mandatory fields are unfilled. Moreover, utilizing function types like S (which typically indicates 'success' rather than 'exit') or using LOOP AT SCREEN to manipulate fields directly would not properly enforce exit logic and might lead to inconsistencies in user interactions. The focus