Network Designers Plan to Interconnect Two Geographically Separated Data Centers

Network designers plan to interconnect two geographically separated data centers using an Ethernet- over-MPLS pseudowire. Within that design, the link between the sites is stable, there are no apparent loops in the topology, and the root bridges for the respective VLANs are stable and unchanging. What additional aspect of the design should be adjusted to mitigate the chance of connectivity issues to the peer data center when the connection takes place?

A) Enable 802.1d on one data center, and 802.1w on the other.
B) Ensure that the spanning tree diameter for one or more VLANs is not too large.
C) Enable UDLD on the link between the data centers.
D) Enable root guard on the link between the data centers.