In RMAN， when the RESYNC CATALOG command is issued， in which two situations does the command file actually perform synchronization？（）

• A、After the COPY command.
• B、After adding a data file in the target database.
• C、After adding a tablespace in the target database.
• D、After adding a tablespace in the catalog database.
• E、After dropping a data file in the catalog database.
• F、After running SQL Loader to load a large amount of data.