Refer to the exhibit. In the diagram, the switches are running IEEE 802.1w RSPT. On which ports should root guard be enabled in order to facilitate deterministic root bridge election under normal and failure scenarios? （）

• A、GE-3/1，GE-3/2
• B、FE-2/1，FE-3/2
• C、GE-1/1，GE-1/2
• D、GE-4/1，GE-4/2
• E、GE-2/1，GE-2/2
• F、GE-3/1，GE-3/2，GE-4/1，GE-4/2，FE-2/1，FE-3/2