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A clique in a simple undirected graph is a complete subgraph that is not contained in any larger complete subgraph. In Exercises 19-21 find all cliques in the graph shown. 19. A dominating set of vertices in a simple graph is a set of vertices such that every other vertex is adjacent to at least one vertex of this set. A dominating set with the least number of vertices is called a minimum dominating set. In Exercises 22-24 find a minimum dominating set for the given graph