Step 1: Understanding the Concept:
The question asks for the specific term used to describe an organization of workers that collectively advocates for its members' rights and interests concerning pay, benefits, and workplace environment.
Step 2: Detailed Explanation:
Trade Union: A trade union, or labor union, is an organization of workers who have come together to achieve common goals. The primary purpose is to protect and advance the interests of its members in the workplace through collective bargaining with employers over wages, working hours, benefits, and safety conditions. This matches the definition given in the question perfectly.
Employee Welfare Trust: This is a trust set up by an employer for the benefit of its employees, often focusing on healthcare, retirement, or other welfare activities. It is managed for the employees but is not an organization formed {by} the workers to negotiate with the employer.
Workplace Intervention Programmes: These are specific programs designed to address issues within a workplace, such as safety problems, harassment, or productivity. They are initiatives, not permanent organizations of workers.
Social Security Association: This term typically refers to government or quasi-government agencies that administer social security programs, such as retirement, disability, and unemployment benefits for the general population, not a worker-formed organization for collective bargaining.
Step 3: Final Answer:
Based on the definitions, the correct term for an organization of workers formed to address members' interests in wages, benefits, and working conditions is a Trade Union.