When executed with the -s option, the superuser privilege is granted to the new user.
※This sample exam is different from those that appear in the actual OSS-DB Exam.
To create a database user, execute the createuser command from the OS command line, or connect to the database with psql and execute the CREATE USER statement. In the PostgreSQL implementation there is no distinction between users and roles, so you can create roles with these commands. In SQL, you can use the CREATE ROLE statement, but there is no command called createrole.
To execute the createuser command you need CREATEROLE privilege. There is also the authority CREATEUSER (deprecated), but since it is the same privilege as the superuser, it is not required to run the createuser command.
You can give privileges to new users by executing createuser with options. The -d option grants database creation authority, the -r option authorizes user (role) creation, and -s superuser privilege. To grant superuser privileges, the user who executes createuser itself must have superuser privileges.
Therefore, the correct answers are C and E.