The 37% of Successful Connects suggest that 63% failed - however, these are spread between both LD_Testbed_MD and LD_RS_Support. If the only AP with connection issues was LD_RS_Support then the reverse math may have worked.

In the IEEE 802.1X authentication process, the AP acts as an authenticator.
According to the Lecture 5 - Security - Part 1 document, the AP's role in the IEEE 802.1X authentication process is to act as an authenticator. This means that the AP acts as a gatekeeper between the client device (supplicant) and the RADIUS server (authentication server). The AP forwards authentication messages between the supplicant and the server and grants or denies network access based on the server's response.
References:
http://faculty.georgebrown.ca/~jolenewa/courses/comp3049-intermediate-wirel/lecture-5-security.pdf

Once a client discovers an access point, the correct order of steps for successful 802.1X authentication is Open System Authentication -> Association -> 802.1X Authentication. So the correct answer is D.Open System Authentication -> Association -> 802.1X Authentication.

According to the Wi-Fi - Radio Modulation - TutorialsPoint document1, 64 QAM is a modulation method that will result in the highest theoretical data rates among the given options. 64 QAM uses both phase and amplitude modulation to encode six bits of information into each transmitted symbol. It can achieve up to 54 Mbps in the 802.11a and g systems.
References: https://www.tutorialspoint.com/wi-fi/wifi_radio_modulation.htm