Explanation:
The V$SYSTEM_EVENT view is used for information on total waits for an event, so I will query this view to monitor cumulative total waits for all events and all sessions..
Incorrect Answers:

1: There is no V$SYS_EVENTS view in Oracle.
3: The V$SESSION_WAIT view is used to list the resources or events for which active sessions are waiting, where WAIT_TIME = 0 for current events.
4: There is no V$SYSTEM_STATUS view in Oracle.
Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 766-767. Chapter 16: Introducing Database Tuning

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