6. (10 points, 5 points each) Consider this relation on the set of vertices of a graph G (V, E): (a, b) | (a, be E } Indicate (by circling) if the relation is reflexive, symmetric, antisymmetric and/or transitive for ALL graphs that meet the given criteria and have at least two vertices. a. A directed acyclic graph Reflexive Symmetric Antisymmetric Transitive b. An undirected simple graph in a star topology with one central vertex v such that E = {(v, x) | x E V, v* x } . See figure below for a "star" graph with six vertices. Reflexive Symmetric Antisymmetric Transitive