A voice engineer is setting up Cisco Jabber IM and must provide visibility for users not on their contact list. Which feature must be enabled to allow this visibility?
A. Availability Sharing
B. Offline Messaging
C. Ad-Hoc Presence Subscription
D. Instant Messaging
Configure Ad-Hoc Presence Subscription Settings
These settings allow users to initiate ad-hoc presence subscriptions to users that are not on their contact list.
https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/im_presence/configAdminGuide/11_0_1/CUP0_BK_C36EBE60_00_config-admin-guide-110/CUP0_BK_C36EBE60_00_config-admin-guide-110_chapter_01010.html#CUP0_TK_C9A10ECA_00