Which statement is correct about the Cisco QoS SDM wizard？（）

• A、the best-effort class will need to have its percentage entered in the QoS Policy Generation screen
• B、SDM QoS wizard provides real-time validation of application usage of WAN bandwidth
• C、the SDM wizard is not able to monitor QoS policing traffic
• D、the SDM QoS wizard is pre-installed on enterprise routers