Final answer:
The WLAN standards that can operate in the 5 GHz frequency band are 802.11a, 802.11n, and also the latest 802.11ac. Standards 802.11b and 802.11g function only in the 2.4 GHz band.
Step-by-step explanation:
The wireless LAN (WLAN) standards that can operate in the 5 GHz frequency band are 802.11a, 802.11n, and also the latest 802.11ac (which is not listed in the options provided but is relevant to the subject).
Specifically, 802.11a was one of the first standards to operate exclusively in the 5 GHz band. The 802.11n standard can operate in both the 2.4 GHz and 5 GHz bands, providing increased flexibility and support for higher data rates. However, standards like 802.11b and 802.11g operate solely in the 2.4 GHz band and do not support operation in the 5 GHz band.
The 5 GHz band is often preferred for its capacity to support higher data rates and its generally less congested spectrum, which leads to fewer interference issues compared to the 2.4 GHz band. In a WLAN context, utilizing the 5 GHz frequency can result in better wireless performance for activities that require high bandwidth such as streaming video or gaming.