A network administrator is managing network traffic so that classified services and applications are prioritized.

Quality of Service (QoS) is used to prioritize certain types of traffic to ensure critical applications receive the bandwidth, low latency, and low jitter they need—especially during congestion. Network+ objectives cover QoS concepts such as classification, marking, queuing, and policing/shaping to manage how traffic is handled on interfaces and across links. If the requirement is to prioritize “classified services and applications,” QoS policies can match traffic using ports, protocols, DSCP markings, VLAN tags, or application identifiers and then place that traffic into higher-priority queues or reserve bandwidth for it. Load balancing distributes traffic across multiple servers/paths but does not inherently prioritize one class of traffic over another on congested links. TTL (time to live) is an IP header field used to prevent routing loops and is unrelated to prioritization. A CDN improves content delivery and caching for distributed users, but it is not a traffic-prioritization mechanism within an organization’s network. Therefore, QoS is the correct technology for prioritizing specific services and applications.