Which SIP trunk deployment model is shown in this enterprise VoIP topology?

Refer to the exhibit.

Which SIP trunk deployment model is shown in this enterprise VoIP topology?
A . mixed TDM and VoIP
B . centralized
C . hybrid
D . traditional TDM
E . distributed

Answer: C

Explanation:

Hybrid SIP Trunk Model In a hybrid SIP trunk deployment, some of the businesses’ sites conform to a distributed SIP trunk deployment model. In this model each site has direct SIP session connectivity to the IP PSTN, and other sites conform to a centralized SIP trunk deployment, accessing the IP PSTN through a central hub, which has SIP session connectivity to the IP PSTN (Figure 3). The hybrid SIP trunk deployment model may have multiple “central” hubs in different geographic regions, or for specific business functions, such as call centers.

Figure 3 Hybrid SIP Trunk Deployment Mode

Reference: http://www.cisco.com/c/dam/en/us/products/collateral/unified-communications/unified-border-element/cis_45835_cube_assets_wp1e.pdf