Players one, two, and three simultaneously and independently choose integers from Si = {4, 5, 6, 7, 8}. If the sum of the three integers is at least 13, each player receives a payoff of 200 minus her choice. Otherwise, each player's payoff is 0. Part A: Find Bi. Explain. Part B: Find Ri. Explain. Part C: Find all (pure strategy) Nash equilibria. Explain