Help please!

Autum Homework: HW Chapter 13 Score: 0 of 1 pt 7 of 26 (6 complete) 13.6-6 In the ultimatum game, one reason players don't choose the rational offer is A. that there are too many possible outcomes to reasonably consider O B. most people believe in reciprocity, and will therefore get even if the prosper treats them badly O C. that it is not a Nash equilibrium. O D. they are worse off by taking the offer