Network Functions Virtualization (NFV) is the correct answer because it provides the ability to manage network functions like VPNs and intrusion prevention systems as virtual services rather than through physical hardware. This technology directly addresses the need for scalability and reduction in operational expenses by allowing for the dynamic deployment and management of virtual network services. While SDN facilitates centralized management and efficiency, and MPLS optimizes data flow across the network, neither provides the functionality to virtualize network services in the manner that NFV does.