Refer to the exhibit.

An administrator implements the MultiZone feature. The administrator sets up five zones as shown in the exhibit.
-Zone A has six controllers that form a cluster.
-Zone B has three controllers that from a cluster.
-Zones C, D, and E have a single standalone controller each.
A total of 13 VAPs are created across the five zones. A zone needs to accept RAP connections form branch offices. All zones have the same AP Group name.
One of the zones will not accept connections from the MultiZone APs.
Which could be a cause of this problem?