When IP phone A was provisioned in a Cisco Unified Communications Manager, 2001 was configured
as the directory number for its first line. Also, bob@cisco.com was defined as the only directory URI
on the Directory Number configuration page for this line. A few days later, an end user was created
in the same Cisco Unified Communications Manager and was associated with the same phone with
the primary extension set to 2001. Also, bobby@cisco.com was defined as a directory URI for that
end user.
Which option about the primary directory URI for IP phone A is true?

A.
bob@cisco.com

B.
bobby@cisco.com

C.
It depends on which radio button was selected next to the Directory URI entries on the Directory
Configuration page.

D.
Both are primary directory URIs in a manner like a shared line for DNs.

E.
Neither are primary directory URIs for IP phone A.

Explanation:

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_system-guide_chapter_0101111.html