Which is the BEST example of the concept of cooperation during America's westward expansion? A) Ranchers and cowboys competed with rustlers and often came in conflict with the townspeople they met during cattle drives. B) European Americans formed communities and helped each other succeed in this new land through activities like barn raisings. C) Mexicans who were living in land surrendered by treaty to the United States faced discrimination after the Mexican-American War. D) Asian immigrants were often paid less than white workers and suffered from discrimination at the work sites because of their unique culture.