Examine the following RMAN script: Which statement describes the purpose of the script?（）

AThe data file is checked for physical corruption and backed up if found clean.

BThe backup of data file 5 is performed and the interactive messages during the backup are suppressed.

CThe existing backup for the data file is checked and the backup is performed if there are changes in the data file after the last backup.

DThe backup of data file 5 is performed and all SQL statements that are executed during RMAN compilation and their results are displayed