How should directory number of the phone and the Cisco Telepresence endpoint be configured in the Cisco Unified CallManager?

How should directory number of the phone and the Cisco Telepresence endpoint be configured in the Cisco Unified CallManager?

A.
As a shared line where the codec and IP Phone share the same directory number

B.
As a single line for the codec and a single line for the phone using the same directory number

C.
As an overlay line using the same directory number

D.
As a single line for the phone and it only has a directory phone number. The codec uses the IP address of the phone