问题：

[单选]

The Company network is displayed in the following topology exhibit：

Workstation 1 traffic is set for cos 5 and the switch CompanyA sends workstation 1 traffic to the  switch CompanyB. However， not all of the traffic from Switch CompanyA is from workstation 1.  Switch CompanyA configurations Switch CompanyB Configuration：  
mlsqos mls qos  
interfacefa0/1 interface fa0/1  
switchportmode trunk switchport trunk mode  
switchporttrunk encapsulation dot 1q switchport trunk encapsulation dot 1q  
switchporttrunk native vlan 1 switchport trunk native vlan 1  
Frames from Workstation 1 are given the rightful priority through Switch CompanyA， but Switch CompanyB doesn’t reciprocate， and treats Workstation 1 frames as if they have no precedence. Which of the following actions will prioritize traffic from Workstation 1？（）

A .  Configure qos all command under Switch CompanyB fa0/1 interface.
B .  Configure mls qos trust cos command under Switch CompanyB fa0/1 interface.
C .  Configure mls qos trust cos 5 command under Switch CompanyB fa0/1 interface.
D .  Configure qos cos 5 command under Switch CompanyB fa0/1 interface.
E .  Configure mls qos trust cos command under Switch CompanyA fa0/1 interface.
F .  Configure qos cos 5 command under Switch CompanyA fa0/1 interface.