What keyword is used to define a standard selection screen in an ABAP report?

The keyword used to define a standard selection screen in an ABAP report is "SELECTION-SCREEN." When you declare a selection screen using this keyword, you are essentially creating a user interface that allows users to input parameters and make selections before executing the report.

Selection screens are vital for ABAP reports as they enable user interaction, allowing users to specify criteria for data retrieval or processing. This can include fields for entering dates, numbers, or other types of data relevant to the report. The creation of the selection screen defines the layout, data structures, and logic needed to validate and process the user inputs when the report runs.

The other options relate to different aspects of ABAP programming. The keyword "PROGRAM" is used to define the name of the program itself, while "REPORT" is utilized to indicate that the program will be a report program. "PARAMETERS" is a keyword used within the selection screen to define specific input fields for user-defined parameters but does not define the selection screen itself. Therefore, the understanding and application of "SELECTION-SCREEN" are crucial for effectively creating user-interactive ABAP reports.