Refer to the exhibit. The trunk does not work over the back-to-back link between Switch1 interface Gig1/0/20 and Switch2 interface Gig1/0/20. Which configuration fixes the problem?
A. Switch 1(config)#interface gig1/0/20
Switch1(config-if)#switchport mode dynamic auto
B. Switch2(config)#interface gig1/0/20
Switch2(config-if)#switchport mode dynamic desirable
C. Switch2(config)#interface gig1/0/20
Switch2(config-if)#switchport mode dynamic auto
D. Switch1(config)#interface gig1/0/20
Switch1(config-if)#switchport trunk native vlan 1
Switch2(config)#interface gig1/0/20
Switch2(config-if)#switchport trunk native vlan 1
Correct Answer: B