Imagine that the ultimatum game is played with two utilitarian agents who each have utility functions . In this representation, the agent offering the ultimatum gains a payoff equal to (as chosen by the agent) if the receiver accepts the ultimatum and if the ultimatum is rejected. The agent deciding whether to accept or reject the ultimatum receives payoff if accepting and if rejecting the ultimatum. Find the unique subgame-perfect equilibrium for this game.Natural selection should seem to favor selfishness. One might reasonably expect more evolutionary success to accumulate for those who maximize their own resources at the expense of others. Nonetheless, altruistic behaviors and cooperative interactions are observed in MANY biological systems. Offer an explanation for (a) mechanism(s) by which natural selection promotes unselfish behavior