The output of show spanning-tree instance 4 on three HP E5406 zl Series switches indicates that all three
switches are the Root of MST instance 4. What is a possible explanation of this result?

A.
The switches have identical Bridge Priorities.

B.
The switches have different MST configuration revisions.

C.
The switches are running different software versions.

D.
The switches have identical Port Priorities for ports associated with the instance.