1. Prove, disprove (give a counterexample, highlight the incorrectness or give the correct answer) or complete a proof. (f) Let be a partition-cut of a connected graph G. If the subgraphs of G induced by the vertex sets X1 and X2 are connected, then may not be a minimal edge-cut. Proposition: A subgraph H of a connected graph G is a subgraph of some spanning tree if and only if H is acyclic