Many proposers in the ultimatum game offer half to the responder with whom they are paired. This behavior could be motivated by (select as many as might apply):

a. Fear that an unequal split might be rejected by a fair-minded responder.

b. A desire to induce the responder to reject the offer.

c. A strong sense of fairness on the part of the proposers.

d. Unrestrained greed on the part of the proposers.