The correct answer is B.
OBJ-1.5: The IEEE 802.1X Port-based Network Access Control framework establishes several ways for devices and users to be securely authenticated before they are permitted full network access. The actual authentication mechanism will be some variant of the Extensible Authentication Protocol (EAP). EAP allows lots of different authentication methods, but many use a digital certificate on the server and/or client machines. This allows the machines to establish a trust relationship and create a secure tunnel to transmit the user authentication credential.