Which of the following is NOT a wireless access technology?

The correct choice is USB 3.0 because it is a wired communication standard rather than a wireless access technology. USB (Universal Serial Bus) is designed for connecting devices to a host computer through physical cables, enabling direct communication and power transfer. It is widely used for various peripherals such as keyboards, mice, and external storage devices.

In contrast, Bluetooth, 802.11x (which refers to Wi-Fi standards), and Zigbee are all technologies that enable wireless communication. Bluetooth (802.15.1) facilitates short-range data exchange between devices, 802.11x covers multiple Wi-Fi standards for local area networking, and Zigbee (802.15.4) focuses on low-power, low-data rate wireless communication, particularly for application areas like home automation and industrial control.