What is the purpose of a role?

A.
To group a collection of privileges together so that they can be simultaneously granted to
and revoked from multiple users.

B.
To establish a credible relationship between DB2 and an external entity, such as a
database administrator or a middleware server

C.
To define exactly what a specific user can do within a particular database once they have
been authenticated.

D.
To group a collection of users together so that they can be simultaneously granted and
revoked specific authorities and privileges.