Why would you use VLANs in a network?

Using VLANs (Virtual Local Area Networks) in a network primarily enhances performance and security by segmenting network traffic. VLANs allow a network administrator to create logically separate networks within the same physical infrastructure. This segmentation can improve overall network performance by reducing broadcast domains; without VLANs, all devices in a broadcast domain receive all broadcast traffic, which can lead to unnecessary congestion.

Additionally, VLANs provide security benefits by isolating sensitive data. For example, different departments or user groups can be placed on separate VLANs to restrict access and limit exposure to sensitive information. This way, even if users are on the same physical switch, their communications can be kept private thanks to the logical separation provided by VLANs.

The choice also provides flexibility in managing the network, allowing devices to be grouped by function rather than physical location, which can greatly enhance the efficiency of network management. Overall, using VLANs supports both performance improvement and enhanced security within a network environment, making option C the correct answer.