Which of the following is a benefit of using a VLAN?

Choosing to implement VLANs indeed primarily enhances network security by segmenting traffic. VLANs (Virtual Local Area Networks) allow network administrators to create logical groupings of devices within the same physical network. By separating traffic from different user groups, departments, or application types, VLANs limit the ability for malicious users to access sensitive information by isolating network segments. This segmentation reduces the risk of unauthorized access and can also contain broadcast traffic, which can improve performance and reduce the likelihood of network congestion.

In addition to security, VLANs help in managing network structure and policies more effectively, as traffic can be controlled and monitored on a per-VLAN basis. While the other options present some relevant aspects, they do not directly relate to the principal advantage of VLANs. For instance, VLANs do not increase the number of available IP addresses inherent to a network; they simply allow for more effective management of existing address space. The enhancement of physical cabling efficiency is also not a direct outcome of VLAN implementation, as VLANs primarily operate at the data link layer regardless of the physical cabling. Finally, VLANs do not act as firewalls; they provide traffic segmentation but do not filter or block traffic like a firewall would.