Which three statements are true about the stages of database startup？（）
- AData files and redo log files can be renamed at the MOUNT stage.
- BControl files are read at the OPEN stage for the location of data files.
- CControl files are required to bring the database to the NOMOUNT stage.
- DData files and redo log files are made available to users at the OPEN stage.
- EData files and online redo log files are checked for consistency while opening the database