Refer to the exhibit. A multilayer switch has been configured to send and receive encapsulated and tagged frames. VLAN 2013 on the multilayer switch is configured as the native VLAN. Which option is the cause of the spanning-tree error?
A. VLAN spanning-tree in SW-2 is configured.
B. spanning-tree bpdu-filter is enabled.
C. 802.1q trunks are on both sides, both with native VLAN mismatch.
D. VLAN ID 1 should not be used for management traffic because its unsafe.
