Which option correctly describes a function of QoS?

• A. QoS allows you to control bandwidth.
• B. QoS assigns IP addresses via DHCP.
• C. QoS blocks all traffic by default.
• D. QoS performs load balancing across servers.

Answer: (A)

Quality of Service focuses on managing how data flows over a network by classifying traffic and applying rules that prioritize some types of traffic and allocate bandwidth accordingly. This lets critical apps like VoIP or video conferencing get the bandwidth and low latency they need, even when the network is busy, while less important traffic uses whatever capacity is left. So the statement that QoS allows you to control bandwidth captures the essence of what QoS does. The other options describe functions outside QoS: DHCP handles IP address assignment, QoS does not block all traffic by default, and load balancing across servers is a feature of load balancers rather than QoS.