An AIX system has a rootvg plus a separate volume group for database application. Which of the following commands are sued to backup the entire system?（）

• A、smitty mksysb (select additional volume group)
• B、mkszfile && mksysb /dev/rmt0
• C、smitty mksysb AND smitty savevg
• D、smitty savevg (select additional volume group)