## **Core Concept**
The appointment of a welfare officer in factories is mandated by labor laws to ensure the well-being and safety of workers. This role is crucial in maintaining a healthy work environment and addressing workers' concerns. The specific threshold of workers that necessitates the appointment of a welfare officer is defined by regulatory standards.

## **Why the Correct Answer is Right**
The correct answer, **1000 workers**, is based on the Factories Act, which stipulates that in factories where the number of workers employed is 1000 or more, a welfare officer is required to be appointed. This officer is responsible for promoting the welfare of workers, ensuring compliance with labor laws, and addressing any grievances or issues that may arise.

## **Why Each Wrong Option is Incorrect**
- **Option A: 100 workers** - This is a threshold for other regulatory requirements under the Factories Act, such as the appointment of a safety officer, but it is not the correct threshold for the appointment of a welfare officer.
- **Option B: 500 workers** - While certain regulatory requirements may apply at this threshold, it is not the specified number for the mandatory appointment of a welfare officer.
- **Option D: 2000 workers** - This is above the correct threshold and, therefore, not the correct answer.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the welfare officer's role is distinct from that of a safety officer or an occupational health professional, although there can be overlap. The welfare officer focuses on the general well-being, safety, and grievances of workers, making this a critical appointment in larger workplaces.

## **Correct Answer:** . **1000**