What are the three configuration requirements for implementing Modular QoS on a router? (Choose three.)

CoS (Class of Service) is a Layer 2 802.1p VLAN marking value used to indicate traffic priority; it is a field that can be matched in a class-map but is not itself an MQC configuration component.

A class-map is required to define the traffic classification criteria, such as matching DSCP values, ACLs, or protocols, grouping packets into logical traffic classes for QoS treatment.

IP Precedence is a ToS field marking used to classify traffic priority at Layer 3; it is a value that may be set or matched in MQC but is not a required structural building block of the MQC framework.

A service-policy command is required to attach a named policy-map to a specific interface or sub-interface in either the inbound or outbound direction, activating the QoS policy.

'priority' is a queuing action keyword used inside a policy-map class to configure low-latency queuing, not a standalone configuration requirement of the MQC framework.

A policy-map is required to associate each class-map with specific QoS actions such as bandwidth allocation, queuing, policing, or shaping, defining the treatment for each traffic class.