Which of the following is NOT a type of wireless security protocol?

The correct answer is D, because Wi-Fi Protected Setup (WPS) is not a security protocol but rather a network security standard designed to simplify the process of connecting devices to a wireless network securely. WPS aims to enable users to easily establish a secure connection between devices like routers and printers without needing to enter lengthy encryption keys.

In contrast, WEP, WPA, and WPA2 are all wireless security protocols that provide encryption and authentication to protect wireless networks from unauthorized access. WEP was one of the first security protocols used but is now considered outdated and insecure. WPA was introduced as a more secure option, and WPA2 further enhanced security by including stronger encryption standards like AES (Advanced Encryption Standard). Thus, WPS serves a different purpose focused on connectivity convenience rather than providing a method for securing data on a wireless network.