2.1. Boys and girls are dancing together at a party. Let D(G,B) denote the statement that girl G danced with boy B at some point during the party. Determine which of the following statements imply another of the statements: (a) (G)(B)D(G,B); (b) (B)(G)D(G,B); (c) (B)(G)D(G,B); (d) (G)(B)D(G,B); (e) (G)(B)D(G,B); (f) (G)(B)D(G,B)