Answer:
a. 802.11b
Explanation:
The 802.11b standard was the first technology for Wi-Fi wireless network interaction to achieve mass acceptance with customers. It is one of many norms in the 802.11 family of Institute of Electrical and Electronics Engineers (IEEE).
Wi-Fi Protected Access (WPA) is a wireless encryption protocol Deprecated ; started implementing the 802.11b standard.It uses the Temporal Key Integrity Protocol (TKIP) vice Cyclic Redundancy Checking (CRC) .
It is also used as a set of encryption key for users authentication.