Which command should be included in order to trust the DSCP-marked traffic from the distribution layer?

A.
mls qos trust cos

B.
mls trust dscp-cos

C.
mls qos trust dscp

D.
mls qos trust dscp-cos

Explanation:

To configure the multilayer switching quality of service port trust state and to classify traffic by examining differentiated services code point (DSCP) value, use the mls qos trust dscp command in interface configuration mode. This will enable the device to trust incoming packets that have DSCP values (the most significant 6 bits of the 8-bit service-type field).

http://www.cisco.com/en/US/products/hw/switches/ps5023/products_tech_note09186a0080883f9e .shtml