Which of the following is an essential feature of a WLAN?

The essential feature of a Wireless Local Area Network (WLAN) is wireless communication between devices. This capability allows devices such as laptops, smartphones, and tablets to connect to the network without the need for physical cables, making it an ideal solution for mobility and flexibility in various environments.

In a WLAN, devices communicate over radio waves, enabling users to access network resources from different locations within the coverage area of the access points. This wireless communication is what fundamentally distinguishes WLANs from traditional wired networks, where devices are connected through cables.

The other options, while perhaps pertaining to network functionality in various contexts, do not accurately represent the core principle of a WLAN. Hardwired connections are a defining characteristic of wired networks, reliance on a single access point would limit the coverage and scalability of a WLAN, and using fiber optics exclusively pertains to a specific type of wired network infrastructure, not wireless communications. Therefore, the capability for wireless communication is the defining feature that makes a WLAN a WLAN.