North Korea's leader Kim Jong-un plays a game with the United States: He decides whether to keep or dismantle his nuclear weapons, while the US decides whether or not to provide him with economic aid. The ordinal payoff matrix for this game is shown below. United States Aid Don't aid North Korea (Kim Jong-un) Dismantle 3, 31, 4Don's dismantle 4, 12, 2a)Draw the game tree for the case when North Korea moves first. What are the rollback equilibrium and equilibrium outcome? b)Draw the game tree for the case when the United States moves first. What are the rollback equilibrium and equilibrium outcome? c)In the case when North Korea moves first, is it possible for the United States to achieve its best outcome by credibly declaring a strategic move in the pregame? If not, why not? If so, what sort of strategic move would the United States use, and how might it phrase its declaration? d)In the case when North Korea moves first, is it possible for the United States to achieve its second-best possible outcome by credibly declaring a strategic move in the pregame? If not, why not? If so, what sort of strategic move would the United States use, and how might it phrase its declaration?