When troubleshooting the issue， you notice the election of a new root bridge with an unknown MAC address. Knowing that all access ports have the PortFast feature enabled， what would be the easiest way to resolve the issue without losing redundant links？（）

• A、Enable bpduguard globally.
• B、Enable rootguard.
• C、Enable loopguard.
• D、Enable spanning tree.
• E、Enable UDLD