You need to determine where the trust boundaries will be in a new Company VOIP design.  Which  two statements are true about these trust boundaries？（）

• A、Trust boundaries are configured in the core of the network to provide the most efficient  forwarding based upon QoS markings，
• B、Setting trust boundaries at the edge of the network allows intermediate hop devices to  administer QoS policies without detailed packet identification.
• C、Trust boundaries are used to determine which QoS mechanism will be applied to the traffic.  
• D、At the trust boundaries， the untrusted traffic will be marked with a new QoS value appropriate  for the policy in place at the point where the traffic entered the campus network.  
• E、Trust boundaries define the firewall rules for QoS admission into a network.