Which three steps must be completed in order to assign a service URL to an IP Phone button? (Choose three.)

A.
Add an IP phone service.

B.
Assign the IP phone service partition to the CSS of the phone.

C.
Create a phone button template that includes a service URL and assign it to the phone.

D.
Create a softkey template that includes a service URL and assign it to the phone.

E.
Subscribe the phone to the service.

F.
Associate a valid user profile with the phone.