Final answer:
The groups that fought to gain better working conditions and pay for workers are Labor Unions. They sought to protect workers from exploitative industrial labor conditions and have been a central force for worker rights, especially during the Progressive Era.
Step-by-step explanation:
These groups fought to gain better working conditions and pay for workers, and the correct answer is c) Labor Unions.
Labor unions are organizations that advocate for the rights and interests of workers, including better wages, reasonable work hours, safer work environments, health benefits, and support programs for workers. They arose from a need to protect workers against the often exploitative conditions of industrial labor, such as long hours, low pay, and unsafe working conditions. The labor movement has been pivotal in negotiating for worker rights and has left a significant impact on the American workforce throughout the Progressive Era and into the modern day.
Organizations like the National Labor Union, Knights of Labor, and the American Federation of Labor played key roles in advocating for labor rights. While there have been various setbacks, including negative reactions to violent strikes and internal differences, unions have evolved and increased their influence, particularly during significant periods such as the Progressive Era under Franklin D. Roosevelt's administration.