【单选题】如下图所示,3com和Cisco公司的交换机相互连接,在两台交换机之间需传输ULANID为1、10、20和30的4个VLAN信息,Catalyst 3548交换机VLAN Trunk的正确配置是
A.
Switch-3548 (config-if) #switchport trunk encapsulation dot 1 q Switch-3548 (config-if) #switchport trunk allowed vlan 1,10,20,30
B.
Switch-3548 (config-if) #switchport mode trunk Switch-3548 (config-if) #switchport trunk encapsulation isl Switch-3548 (config-if) #switchport trunk allowed vlan 1-30
C.
Switch-3548 (config-if) #switchport mode trunk Switch-3548 (config-if) #switchport trunk encapsulation negotiate Switch-3548 (config-if) #switchport trunk allowed vlan 1-30
D.
Switch-3548 (config-if) #switchport mode trunk Switch-3548 (config-if) #switchport trunk encapsulation dot 1q Switch-3548 (config-if) #switchport trunk allowed vlan 1,10,20,30