※This sample exam is different from those that appear in the actual OSS-DB Exam.
In PostgreSQL you can change the attributes and privileges of users with ALTER USER (or ALTER ROLE). However, attributes and permissions that can be changed are limited to those that can be set at user creation in CREATE USER.
When creating a user, you can specify the name and password of the user, whether you have super user authority, whether you have authority to create users, whether you have authority to create the database, and so on. Both of these can be changed with the ALTER USER statement.
Creating a table requires the CREATE privilege for the schema, which is a privilege that can only be granted by the GRANT statement.
Therefore the correct answer is C.