Which three statements are true about an spfile? (Choose three)
A. It contains only static initialization parameters.
B. It is the first file processed at instance startup.
C. It can be edited by SYS when the database instance is shut down.
D. It must exist for a database instance to start.
E. It can be used to create a pfile.
F. It contains initialization parameters whose values can be changed using the ALTER SYSTEM command.