Which one of these options is not a valid reason for a client to become excluded?

Which one of these options is not a valid reason for a client to become excluded?
A. excessive 802.11 association failures
B. excessive 802.11 authentication failures
C. excessive 802.1X association failures
D. excessive 802.1X authentication failures
E. an attempt to use an IP address already assigned to another device
F. excessive web authentication failures