Refer to the exhibit.
R2#show standby
FastEthernetl/O - Group 50
State is Active
2 state changes, last state change 00:04:02
Virtual IP address is 10.10.1.1
Active virtual MAC address is 0000.0c07.ac32 (MAC In Use)
Local virtual MAC address is 0000.0c07.ac32 (vl default)
Hello time 3 sec, hold time 10 sec
Next hello sent in 1.504 secs
Preemption enabled, delay reload 90 secs
Active router is local
Standby router is unknown
Priority 200 (configured 200)
Track interface FastEthernetO/0 state Up decrement 20
Group name is "hsrp-Fal/0-50" (default)
R2#
%IP-4-DUPADDR: Duplicate address 10.10.1.1 on FastEthernetl/0, sourced by 0000.0c07.ac28
R2#
Which option is the most likely explanation of the duplicate address message logged?