Which statement is true about the database and database-user used during installation of IMS Server？（）

• A、A preexisting database user may be used but a new database has to be created during installation.
• B、A preexisting database may be used but a new database user has to be created during installation.
• C、A preexisting database and user may be used or a new database and user are created during installation.
• D、A preexisting database and user cannot be used； a new database and user are created during  installation.