You don't really have any multiple choice, so here's an explanation. The entire reason for early sports was to teach younger generations how to work in a team, so that when they worked in industrial factories and businesses, they had already learned teamwork. Pro sports began to rise in popularity as rivalries between regional areas in the US rose through the progressive era. These rivalries had existed since the antebellum era in America before the civil war. Plus, there weren't many forms of entertainment in the industrial areas, and sports(watching or playing) was a great way to keep individuals off the streets and in a better area. Thus, pro sports popularity rose in the 1900s.
