How did the two groups at robbers cave enter into conflict? a. the two groups were pitted against each other to compete for prizes and resources. b. the two groups were presented with superordinate goals that they were unable to complete. c. the two groups were kept in isolation from each other and told harmful stories about each other. d. the two groups were broken up and reintegrated into different groups, causing conflict. please select the best answer from the choices provided a b c d