EAP-MD5 provides one-way client authentication. The server sends the client a random challenge. The client proves its id

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EAP-MD5 provides one-way client authentication. The server sends the client a random challenge. The client proves its identity by hashing the challenge and its password with MD5.
What is the problem with EAP-MD5?

A. EAP-MD5 is vulnerable to dictionary attack over an open medium and to spoofing because there is no server authentication.
B. EAP-MD5 communication must happen over an encrypted medium, which makes it operationally expensive.
C. EAP-MD5 is CPU-intensive on the devices.
D. EAP-MD5 not used by RADIUS protocol.