Some users report that they cannot dial out from headquarters on their Cisco IP Phones to PSTN
users, but others can.
Which troubleshooting approach is the most direct to isolate the source of the failure of the users
that cannot dial out to the PSTN?

A.
Use DNA to analyze the dialing permissions of the Cisco IP Phones.

B.
Use DNA to generate actual calls to the PSTN.

C.
Use RTMT to analyze the dialing permissions of the Cisco IP Phones.

D.
Use RTMT to generate actual calls to the PSTN.