Choosing a file type while exporting diagram from coreldraw to ms publisher

Hi, 

I have created a diagram in coreldraw, however I need to export the same to ms publisher. My questions:

1. What file type should I export the diagrams in? Should it be EMF? (as this doesn't seem to have a white background)

2. Secondly, while exporting it asks whether you want to keep it as default or vector etc? What would give me better output while printing?

Please let me know ... don't want to mess up during printing. Thanks.