John works as a Network Administrator for Web Perfect Inc. The company has a wireless LAN network. John has configured shared key authentication on a client. The client and the AP start exchanging the frames to enable authentication. Which of the following vulnerabilities may occur while the client and the AP exchange the challenge text over the wireless link?

A.
Land attack

B.
Vulnerability attack

C.
Man-in-the-middle attack

D.
DoS attack