Refer to the exhibit.

The control system depicted in the exhibit uses VLAN 300 for all of its device ports and
PVST is enabled on each switch to switch connection. L2SW4 was inserted between
L2SW3 and L2SW5. Links FO2 and FO3 were added and FO1 was disconnected.
Prior to the installation of L2SW4, PanelView was able to communicate with PLC#1. After
the change, PLC#1 and PanelView are still able to communicate but neither PLC#1 or
PanelView are able to communicate with I/O #1.
L2SW4# show run interfaces FastEthernet 1/1
description I/O#1
switchport access vlan 300
switchport mode access
spanning-tree portfast
spanning-tree bpduguard enable
L2SW4# show interfaces trunk
Port Mode Encapsulation Status Native vlan Gi1/1 on
802.1q trunking 1 Gi1/2 on 802.1q trunking 1
Port Vlans allowed on trunk Gi1/1 1,3-9, 301-305,400 Gi1/2 1,3-9, 301-305,400
Port Vlans allowed and active in management domain Gi1/1 1,3-9, 301-305,400
Gi1/2 1,3-9, 301-305,400 Port Vlans in spanning tree forwarding state and not
pruned Gi1/1 1,3-9, 301-305,400 Gi1/2
Based on the output from the switch, what is preventing I/O#1 from communicating with
PLC#1 and PanelView?

A.
Interface FastEthernet 1/1 on LWSW4 should be configured as a trunk port

B.
The trunks connecting L2SW4 to L2SW3 and L2SW5 have the wrong encapsulation type

C.
The trunks connecting L2SW4 to L2SW3 and L2SW5 don’t allow VLAN 300 traffic

D.
BPDU guard has error-disabled interface FastEthernet 1/1 on LWSW4