为自己加油

Examine the statements that use flashback technologies:

1-FLASHBACK TABLE customers TO TIMESTAMP TO_TIMESTAMP('2013-02-04 09:30:00', 'YYYY-MM-DD HH:MI:SS');

2-SELECT * FROM customers AS OF SCN 123456;

3-FLASHBACK TABLE customers TO BEFORE DROP;

4-FLASHBACK DATABASE TO TIMESTAMP TO_TIMESTAMP('2013-02-04 09:30:00', 'YYYY-MM-DD HH:MI:SS');

5-SELECT * FROM customers VERSIONS BETWEEN SCN 123456 AND 123999;

6-ALTER TABLE customers FLASHBACK ARCHIVE;

Which set of statements depends on the availability of relevant undo data in the Undo tablespace?

A.
1,3,6
B.
1,2,5
C.
3,4,5
D.
2,3,5,6