What role do unions play for workers in terms of labor rights?

Unions play a vital role in advocating for the rights and interests of workers. They represent employees in negotiations with employers regarding wages, working conditions, and benefits, ensuring that workers have a collective voice. Through collective bargaining, unions are able to secure agreements that enhance job security, improve health and safety regulations, and establish fair labor practices. This advocacy is crucial, especially in industries where workers may feel powerless to negotiate on their own due to power imbalances with management.

In contrast, the other options do not accurately reflect the primary role of unions. Limiting layoffs is a benefit that may arise from union activities, but unions do not directly guarantee job security. Preventing competition among workers is not their focus; rather, unions aim to unite workers in solidarity to improve their collective bargaining power. Additionally, promoting management decisions over workers' choices is contrary to the mission of unions, which is to stand up for employees' rights and choices rather than support management's interests. Thus, the emphasis on advocacy for workers is what makes this choice the correct one.