How is the Primary Bridge chosen in a VPLS?

A. The PE devices participating in the VPLS mesh run a separate Spanning Tree instance in the Core. The Primary Bridge is the Root Bridge for the VPLS mesh.

B. The PE devices participating in the VPLS mesh determine which bridge is closest to Root Bridge. This bridge becomes the Primary Bridge.

C. The PE devices participating in the VPLS mesh determine which bridge has the lowest bridge-id. This bridge becomes the Primary Bridge.
D. The PE devices participating in the VPLS mesh determine which bridge is the Root Bridge. This becomes the Primary Bridge.