Full outer join

A developer is using a Joiner transformation to join two data streams (sources), and a full outer join is desired. Select the statement below that is true.

Choose Answer

(A)
A Joiner transformations may perform a full outer join under all conditions.
(B)
A Joiner transformation may perform a full outer join only when one or more sides of the join are from a relational database.
(C)
A Joiner transformation may perform a full outer join only when all sides of the join originate from relational databases, and one or more of those databases support outer joins.
(D)
A Joiner transformation may perform a full outer join only when no file sources are involved in the join (both sides are relational).