Which three are true aboutprivileges and roles?

In Oracle Database 12c, the following are true about privileges and roles:

Option B: PUBLIC acts as a default role granted to every user in a database.

The PUBLIC role is a special role that is automatically granted to all users. It can be used to provide privileges to every user.

Option C: A user has all object privileges for every object in their schema by default.

By default, a user has all privileges on the objects they own, i.e., the objects in their schema.

Option D: A role can contain a combination of several privileges and roles.

Roles are designed to group together privileges and other roles, making it easier to manage and assign security settings to users.

Options A, E, F, and G are incorrect because:

Option A: System privileges can be set for specific schemas or objects, not always for the entire database.

Option E: Roles are not "owned" by users in the traditional sense of ownership; they are managed by the database and can be granted to any user.

Option F: Not all roles are owned by the SYS schema; roles are a database security concept and do not have an "owner".

Option G: The PUBLIC role is not something that can be revoked from a user; it is a default role that exists for all users.