Certkiller has three locations connected via an IP WAN. Each location has a CallManager cluster, and the headquarters cluster is connected to all other clusters via inter-cluster trunks. Certkiller wants to allow up to 8 simultaneous calls across the IP WAN. To call between sites, employees dial a 2 digit access code plus the 4 digit extension. If more than 8 calls are made, or if the IP WAN is not available, calls should be sent to Certkiller’s preferred long distance carrier. If the trunk to the long distance carrier is not available, the local provider should be used. The long distance carrier requires 10 digits to complete a long distance call. The local provider requires 11 digits to complete a long distance call but only 7 digits for local calls. What is the minimum number of routes required at the headquarters location?

A.
1

B.
2

C.
3

D.
4

E.
5

F.
6