Which of the following wireless standards operates at speeds of 54 Mbps and uses the 5 GHz band?

The correct choice is based on the specific characteristics of the 802.11a wireless standard. This standard was developed as part of the IEEE 802.11 wireless networking protocols and is known for operating in the 5 GHz frequency band. One of its key features is that it supports data rates up to 54 Mbps, which was a significant increase in speed compared to earlier standards that operated at lower speeds and in different frequency bands.

In contrast, the other standards listed operate on different frequencies and have different maximum data rates. For example, 802.11b operates at 2.4 GHz and supports speeds up to 11 Mbps, while 802.11g also operates at 2.4 GHz but allows for speeds of up to 54 Mbps. However, the distinctive feature of 802.11a is its exclusive operation within the 5 GHz band, which helps reduce interference and congestion often found in the 2.4 GHz range. Although 802.11n also supports both 2.4 GHz and 5 GHz operation with potentially much higher data rates, the specific bandwidth and maximum data rate associated with 802.11a clearly make it the correct answer in this scenario.