Assume that local route groups are configured. When an IP phone moves from one device mobility group to another, which two configuration components are not
changed? (Choose two.)

A.
IP subnet

B.
user settings

C.
SRST reference

D.
region

E.
phone button settings

Explanation:
Incorrect answer: A, C, D

Although the phone may have moved from one subnet to another, the physical location and associated services have not changed.
Link: http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/admin/7_1_2/ccmfeat/fsdevmob.html#wp1137460