Suppose we are given a graph G(V,E) representing a computer network where vertices represent routers and edges represent physical connections. Suppose that we want to upgrade some of the routers in our network with special new, but expensive routers that can perform sophisticated monitoring operations for incident connections. We are interested to determine if k new routers are sufficient to monitor every connection in our network. Is the above problem a P or an NP-complete problem? If it is P, give a solution, if not state why it is an NP-complete problem.