which two cases would you use an outer join?

In which two cases would you use an outer join? (Choose two.)

A.
The tables being joined have NOT NULL columns.

B.
The tables being joined have only matched data.

C.
The columns being joined have NULL values.

D.
The tables being joined have only unmatched data.

E.
The tables being joined have both matched and unmatched data.

F.
Only when the tables have a primary key/foreign key relationship.

Explanation:
You use an outer join to also see rows that do not meet the join condition.
Incorrect answer:
Ameet a join condition
Bmeet a join condition
Dmeet non join condition only
Fdoes not take into consideration of primary key and foreign key relationship

Refer: Introduction to Oracle9i: SQL, Oracle University Study Guide, 4-17