Latency is the correct answer as it refers to the time delay experienced in a system, particularly the time it takes for a data packet to travel from its source to its destination. Low latency is crucial for performance-sensitive applications, as it ensures faster communication between services. In contrast, bandwidth is about the volume of data that can be transferred over time, and throughput is the actual rate of data transfer achieved. While NICs (Network Interface Controllers) are responsible for network communications within computers, they are not a metric but a hardware component.