Which three statements are true about the stages of database startup？（）

• A、Data files and redo log files can be renamed at the MOUNT stage.
• B、Control files are read at the OPEN stage for the location of data files.
• C、Control files are required to bring the database to the NOMOUNT stage.
• D、Data files and redo log files are made available to users at the OPEN stage.
• E、Data files and online redo log files are checked for consistency while opening the database