As a network administrator, you want to modernize your network with modular software running on standard server platforms. You want to start by replacing traditional, custom$-$designed network equipment. You also wish to have flexible, cost$-$saving options for many types of network devices, including virtual servers, data storage, load balancers, and firewalls. Which one of the following will you use in such a scenario?

a$.$

SDN $($Software Defined Networking$)$

b$.$

NFV $($Network Functions Virtualization$)$

c$.$

FCoE $($Fibre Channel over Ethernet$)$

d$.$

vSwitch $($virtual Switch$)$