If you needed to transport traffic coming from multiple VLANs （connected between switches）， and  your CTO was insistent on using an open standard，which protocol would you use？（）

A. Configure the D-SW1 switch as the active HSRP router and the STP root for all VLANs. Configure the D-SW2 switch as the standby HSRP router and backup STP root for all VLANs. 
B. Configure the D-SW1 switch as the standby HSRP router and the STP root for VLANs 11 and 110. Configure the D-SW2 switch as the standby HSRP router and the STP root for VLANs 12 and 120.
C. Configure the D-SW1 switch as the active HSRP router and the STP root for VLANs 11 and 110. Configure the D-SW2 switch as the active HSRP router and the STP root for VLANs 12 and 120.
D. Configure the D-SW2 switch as the active HSRP router and the STP root for all VLANs.  Configure the D-SW1 switch as the standby HSRP router and backup STP root for all VLANs. 
E. Configure the D-SW1 switch as the active HSRP router and the backup STP root for VLANs 11  and 110. Configure the D-SW2 switch as the active HSRP router and the backup STP root for  VLANs 12 and 120.
F. Configure the D-SW1 switch as the standby HSRP router and the backup STP root for VLANs 12a nd 120. Configure the D-SW2 switch as the standby HSRP router and the backup STP root  for VLANs 11 and 110.

A.Routing should occur at the access layer ifvoice VLANs are utilized. Otherwise， routing should occur at the distribution layer.
B.Routing should always be performed at the distribution layer.
C.VLANs should be localized to a switch.
D.VLANs should be localized to a single switch unlessvoice VLANs are being utilized.
E.Routing should not be performed between VLANs located on separate switches.