正解:D
Classification is the QoS feature that uses the IP Precedence bits in the ToS field of the IP packet header to partition traffic into different priority levels. It involves identifying and categorizing packets based on the IP Precedence value, which can range from 0 to 7, with higher values indicating higher priority traffic. This process is essential for applying appropriate QoS policies to different types of traffic, ensuring that high-priority traffic, such as voice and video, receives the necessary bandwidth and low latency treatment.
References := Quality of Service (QoS) Configuration Guide, Cisco IOS XE Everest 16.6.x