In our study of behavioral game theory we provided examples showing that players in a game may fail to reach the "fully rational" equilibrium because of "bounded rationality" or because of psychological biases in decision-making.

A. The ultimatum game illustrates bounded rationality.

B. In the ultimatum game full rationality implies equal payoffs for both players.

C. The "beauty contest game" in which players try to guess 2/3 of the average illustrates the importance of the reciprocity norm in decision-making.

D. None of the above.