Explanation:
: The correct statement for Top-N Analysis

 SELECT [coloumn_list], ROWNUM 
 FROM (SELECT [coloumn_list] 
 FROM TABLE 
 ORDER BY Top-N_coloumn) 
 WHERE ROWNUM <= N; 

Incorrect answer :
1: ROWID is not require
2: GROUP BY clause is not require
4: Must have inline view and outer query.
Reference:
Introduction to Oracle9i : SQL, Oracle University Study Guide, 11-23

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