Answer:
B. American Federation of Labor
Step-by-step explanation:
The American Federation of Labor, also known as the AFL, was the largest union in the US and one of the most successful due to its size and composition. This union was led by the Gompers, who managed to claim several labor improvements across the country. Initially, the AFL only allowed qualified workers to be part of the organization, however, as time went by, this requirement gradually lost strength, until it was completely abandoned.