You are the network administrator of a small Layer 2 network with 50 users. Lately， users have been complaining that the network is very slow. While troubleshooting， you notice that the CAM table of your switch is full， although it supports up to 12，000 MAC addresses. How can you solve this issue and prevent it from happening in the future？（）
- AUpgrade the switches
- BConfigure BPDU guard
- CConfigure VLAN access lists
- DConfigure port security
- EConfigure Dynamic ARP inspectio