A.set the SESSIONS to 1 in the parameter file
B.grant SINGLE SESSION privilege to all of the users
C.set the SESSIONS_PER_USER to 1 in the users’ profile
D.grant RESTRICTED SESSION privilege to all of the database users
E.create a role with SINGLE SESSION privilege and assign the role to the users

A.It cannot be created without a package specification.
B.It cannot invoke subprograms defined in other packages.
C.It can contain only the subprograms defined in the package specification.
D.It can be changed and recompiled without making the package specification invalid.