Which of the following statements is true?

A.
The auto-reg-ephone command can automatically create an ephone.

B.
The auto assign command can automatically create an ephone.

C.
The auto-reg-ephone command can automatically create an ephone-dn.

D.
The auto assign command can automatically create an ephone-dn.

Explanation:
The auto-reg-ephone command can automatically create an ephone. When an IP phone registers with a router
that is configured with the auto-reg-ephone command, the router will associate the Media Access Control
(MAC) address of the IP phone with the first unassigned ephone on the router. If all the ephones on the router
are associated with IP phones, the router will create a new ephone, provided that the number of configured
ephones does not exceed the value of the max-ephones command. The max-ephones command specifies the
maximum number of ephones that you can configure on a router.
You can also manually assign an IP phone to an ephone by issuing the mac-address mac-address command in
ephone configuration mode, where mac-address is the MAC address of the IP phone you want to assign to the
ephone. For example, you can issue the following command set to associate an IP phone with the MAC
address 0019:8765:4321 with ephone number 1:
telephony-service
ephone 1
mac-address 0019.8765.4321
The auto-reg-ephone command cannot automatically create an ephone-dn. An ephone-dn must be configured
before it can be assigned to buttons on ephones.
The auto assign command cannot automatically create an ephone or an ephone-dn. The auto assign command
automatically associates button 1 on an ephone with an existing, unused ephone-dn. The ephone-dn is not
automatically created? it must already exist. If no ephone-dn is available, the phone will register but none of the
phone’s buttons will be associated with ephone-dn extensions.

Cisco: Cisco Unified CME Commands: auto-reg-ephone
Cisco: Cisco Unified CME Commands: auto assign