Suppose bob joins a bittorrent torrent, but he does not want to upload any data to any other peers (so called free-riding). a. bob claims that he can receive a complete copy of the file that is shared by the swarm. is bob’s claim possible? why or why not? b. bob further claims that he can further make his "free-riding" more efficient by using a collection of multiple computers (with distinct ip addresses) in the computer lab in his department. how can he do that?