Which statement is most correct regarding vNICs and VLANs?（）

• A、only the default vlan has traffic that is tagged
• B、All vNICs have to be associated with one or more VLANs except for the default vlan
• C、vlan must be configured before configuring them into a vNIC
• D、Tagging is done by the operating system NIC if the flag is set to tag traffic