Explanation:
Privileges can be given to a role by using the CREATE ROLE statement. A user can have access to several roles, and several users can be assigned the same role.
Incorrect Answers:
1: There is no limitation to a 1000 users for one role in Oracle.
2: There is no limitation to a 10 roles for one user in Oracle.
3: There is no limitation to a 1000 privileges for one role in Oracle.
5: The role can act as a named group of privileges to execute certain tasks. But privileges can be not related at all.
OCP Introduction to Oracle 9i: SQL Exam Guide, Jason Couchman, p. 365-373
Chapter 8: User Access Control in Oracle

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