Given: A WLAN protocol analyzer trace reveals the following sequence of frames (excluding the ACK...

The key clue in this sequence is the four EAPOL-Key frames, which indicate a 4-way handshake — a hallmark of WPA and WPA2 authentication processes. There is no EAP exchange preceding the 4-way handshake, which eliminates WPA/WPA2-Enterprise and 802.1X/EAP methods. This points directly to WPA2-Personal, where PSK (Pre-Shared Key) is used and there is no EAP exchange before key generation.

Also, the second "Auth" frame suggests Open System Authentication was used, which is typical for RSN-based networks (not Shared Key as in WEP).