What are the limitations of using a full outer join in a star join node?

What are the limitations of using a full outer join in a star join node? Note: There are 2 correct answers to this question.
A . It must appear in the last DIMENSION in the star join node.
B. It is restricted to one DIMENSION in a star join node.
C. It CANNOT be mixed in the same star join node with other join types.
D. Only one column can be included in the join condition.

Answer: A,B