A．4字节 B．8字节C．16字节 D．35字节STP的拓扑变化通知BPDU的长度不超过_____

A．Switch-6500>(enable)set vlan 110 vlan11
Switch-6500＞(enable)set vlan 120 vlan12
Switch-6500＞(enable)set vlan 110 5/21
Switch-6500＞(enable)set vlan 120 5/22
Switch-6500＞(enable)set trunk 5/23 on dotl q
Switch-6500＞(enable)set trunk 5/23 vlan 110，120
Switch-6500＞(enable)
B．Switch-6500＞(enable)set vlan 110 name vlanll
Switch-6500＞(enable)set vlan 120 name vlanl2
Switch-6500＞(enable)set vlan 110 5/21
Switch-6500＞(enable)set vlan 120 5/22
Switch-6500＞(enable)set trunk 5/23 on ISL
Switch-6500＞(enable)set trunk 5/23 vlan 110-120
Switch-6500＞(enable)
C．Switch-6500＞(enable)set vlan 110 name vlan11
Switch-6500＞(enable)set vlan 120 name vlan12
Switch-6500＞(enable)set vlan 110 5/21
Switch-6500＞(enable)set vlan 120 5/22
Switch-6500＞(enable)set trunk 5/23 on dotl q
Switch-6500＞(enable)set trunk 5/23 vlan 110，120
Switch-6500＞(enable)
D．Switch-6500＞(enable)set vlan 110 name vlan11
Switch-6500＞(enable)set vlan 120 name vlan12
Switch-6500＞(enable)set vlan 110 port 5/21
Switch-6500＞(enable)set vlan 120 port 5/22
Switch-6500＞(enable)set trunk 5/23 on dotl q
Switch-6500＞(enable)set trunk 5/23 vlan 110，120
Switch-6500＞(enable)

STP的拓扑变化通知BPDU的长度不超过______。