正解:A
Quality of Service (QoS) is crucial for real-time services like video conferencing. It prioritizes voice and video packets over less critical traffic (like file downloads), reducing latency, jitter, and packet loss.
B). Network signal may apply to wireless, but it's not specific to video issues.
C). Time to live (TTL) affects packet lifespan, not performance or quality.
D). Load balancing manages traffic across multiple paths but doesn't prioritize real-time traffic like QoS does.
# Reference:
CompTIA Network+ N10-009 Official Objectives: 3.6 - Explain the characteristics of network topologies and types.