Refer to the exhibit. A network engineer is implementing QoS services. Which two statements about the QoS-group keyword on Cisco IOS XR 3re true? (Choose two )

QoS group numbering is an arbitrary identifier used for classification and does not inherently correspond to a specific priority level; priorities are determined by how these groups are used in policies.

QoS group marking, a feature on Cisco IOS XR, is typically performed at the ingress edge of a router or network segment. This initial classification assigns an internal QoS group identifier to packets as they enter the device.

QoS group marking is primarily an internal classification mechanism for local QoS policy enforcement within a device or network segment, not an end-to-end marking for enforcement across an entire service provider network where DSCP or IP Precedence are typically used.

Once packets are marked with a QoS group, this identifier becomes an internal attribute that can be used as a flexible and powerful match criteria within subsequent QoS policies applied to the router's internal fabric or other interfaces, enabling consistent QoS treatment throughout the device.

QoS groups can indeed be used in conjunction with priority traffic classes; they serve as a classification method that can then feed into priority-based scheduling or queuing mechanisms.