## Core Concept
The Employees' State Insurance (ESI) is a social security and health insurance scheme for Indian workers. It provides medical care and cash benefits in the case of sickness, maternity, disability, and death due to employment injury. The ESI Act is a key piece of legislation aimed at protecting workers' rights and ensuring their health and well-being.

## Why the Correct Answer is Right
The ESI Act came into effect on April 7, 1958. This is a significant milestone in India's social security framework, marking the implementation of a comprehensive health insurance and social security scheme for workers. The Act was enacted to provide a safety net for workers in the organized sector and their dependents, ensuring access to medical care and financial support during times of need.

## Why Each Wrong Option is Incorrect
* **Option A:** 1948 - This is the year the ESI Act was enacted, but it did not come into effect immediately. There was a gap between its enactment and implementation.
* **Option B:** 1950 - This is incorrect because the ESI Act did not come into effect in 1950. The actual implementation year is later.
* **Option D:** 1960 - This is incorrect because the ESI Act came into effect two years earlier, in 1958.

## Clinical Pearl / High-Yield Fact
A key fact to remember is that the ESI Act was enacted in 1948 but came into effect on April 7, 1958. This piece of legislation is crucial for understanding the social security framework in India, especially for workers in the organized sector.

## Correct Answer: C. 1958