Explanation:
The Database Resource Manager can estimate, in advance, the execution time of a statement gathering optimizer statistics on related objects.
Incorrect Answers:
1: Setting the TIMED_STATISTICS initialization parameter will not help the Database Resource Manager to estimate the execution time of a statement. TIMED_STATISTICS specifies whether or not statistics related to time are collected.
3: Setting the TIMED_OS_STATISTICS initialization parameter will not help the Database Resource Manager to estimate the execution time of a statement.
TIMED_OS_STATISTICS specifies the interval (in seconds) at which Oracle collects operating system statistics when a request is made from the client to the server or when a request completes.
4: It is required to gather optimizer statistics on related objects to achieve this.
Reference:
OCP Oracle9i Database: New Features for Administrators, Daniel Benjamin, p. 122-129
Chapter 3: Manageability Enhancements

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