Which SIP header is used by Cisco Unified Communication Manager to support the Redirected
Number ID Service?

A.
replaces

B.
RPID

C.
diversion

D.
join

E.
P-charging-vector

Explanation:
CUCM uses sip diversion header in INVITE message to carryout Redirected Number ID service.

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/9_0_1/ccmsys/CUCM_BK_CD
2F83FA_00_cucm-system-guide-90/CUCM_BK_CD2F83FA_00_systemguide_chapter_0101000.html#CUCM_TP_R3F173A9_00