You have implemented 802.1X authentication in your Layer 2 network and you have only a
single RADIUS server. You are asked to ensure that if the RADIUS server becomes
unreachable or fails, users connected to the ge-0/0/0 port are still able to reach the Internet
using a predefined guest VLAN. Which command allows this access?

A.
[edit] user@switch# set protocols dot1x authenticator interface ge-0/0/0.0 radius-fail
assign guest

B.
[edit] user@switch# set protocols dot1x authenticator interface ge-0/0/0.0 radius-fail vlan
guest

C.
[edit] user@switch# set protocols dot1x authenticator interface ge-0/0/0.0 server-fail
vlan-name guest

D.
[edit] user@switch# set protocols dot1x authenticator interface ge-0/0/0.0 auth-fail
assign-vlan guest

Explanation: