What is the most typical use of an overlapping VPN?

What is the most typical use of an overlapping VPN?

A.
Service providers supporting managed CE services.

B.
Service providers supporting carrier-over-carrier MPLS implementations.

C.
Simple intranet VPN implementations.

D.
Companies that use MPLS VPNs to implement both intranet and extranet services.

Explanation:
There are two typical uses for overlapping VPNs:
1) Companies that use MPLS VPNs to implement both intranet and extranet services might use
overlapping VPNs. In this scenario, each company participating in the extranet VPN would
probably deploy a security mechanism on its customer edge (CE) routers to prevent other
companies participating in the VPN from gaining access to other sites in other customer VPN
2) A security-conscious company might decide to limit visibility between different departments in
the
organization. Overlapping VPNs might be used as a solution in this case

Cisco Press – Implementing Cisco MPLS study guide p.6-20