What is a key responsibility of a network administrator regarding network traffic?

A key responsibility of a network administrator is to monitor and manage data traffic. This involves overseeing the flow of data across the network to ensure that it is functioning correctly and efficiently. By monitoring traffic, the administrator can identify patterns, detect anomalies or potential issues, and ensure that bandwidth is used effectively. This task is crucial because it helps maintain the performance and reliability of the network, supporting the needs of users and applications. Effective management also involves configuring equipment like routers and switches, addressing potential bottlenecks, and implementing security measures to protect the data being transmitted.

In contrast, the other options do not align with the primary duties of a network administrator. Running software applications pertains more to software development or user help desk roles, creating user documentation is typically the responsibility of technical writers or instructional designers, and designing marketing strategies falls under marketing or business development professions. Thus, the focus on traffic management distinctly highlights the pivotal role network administrators play in maintaining a well-functioning network.