Ajax has decided to open regional sales offices to put their sales staff closer to their customers. The new offices are located in Oakland, Denver, Chicago, and New York. The Northwest and Southeast regional sales offices are located the Redmond and Atlanta facilities. The sales offices will connect to the Ajax campus via a Frame Relay network. Each site will have a PSTN gateway for local and emergency calls. All calls to and from the regional offices as well as long distance calls should use the IP WAN as much as possible. Call processing and voice mail will remain centralized Atlanta. H.323 gateways will be deployed at the remote sites for PSTN access.
The Ajax central campus and regional sales offices will use the G.711 codec locally. The G.729 codec will be used when calls cross the WAN, and cRTP will be implemented on each link. The voice-mail system only supports G.711.
The DID ranges of the Oakland, Denver, and Chicago sales offices overlap over the last seven digits of the ranges. How can an abbreviated inter site dial plan be developed so that extension 1023 in Oakland doesn’t overlap with extension 1023 in Denver and Chicago?

A.
Dial the last six DID digits.

B.
Dial the last seven DID digits.

C.
Use 11 -digitdialing.

D.
Use a two-digit site code and four-digit dialing.

E.
Use translation patterns with four-digit dialing to route calls properly.