(a) Model the following situation a graphs. Draw the graph, and give the corresponding adjacency matrix Ann and Bob are friends. Ann is also friends with Carla and David. Bob, Carla and Evans are all friends of each other (b) Either draw a graph with the following specified properties, or explain why no such graph A simple graph with five vertices with degrees 2, 3, 3, 3, and 5 (c) How many edges does a graph have if its degree sequence is 5, 2, 2, 2, 2, 1? Draw such a graph (d) The definition of a topological ordering of a graph G V,E> is an ordering of the vertices from 1 to n such that if (i.j) is in E then i