2과목)다음 중 ORDER BY와 ROWNUM에 대한 설명으로 옳은 것은?

SELECT * FROM EMP WHERE ROWNUM = 1 ORDER BY SAL DESC; SELECT * FROM ( SELECT * FROM EMP ORDER BY SAL DESC ) WHERE ROWNUM = 1; SELECT * FROM EMP ORDER BY SAL DESC WHERE ROWNUM = 1; SELECT * FROM EMP WHERE ROWNUM <= 1 ORDER BY SAL DESC;