## Core Concept
The Employees' State Insurance (ESI) Act provides social security and health insurance to Indian workers. Maternity benefits under the ESI Act are designed to support female employees during pregnancy, childbirth, and related medical conditions, including miscarriage.

## Why the Correct Answer is Right
The ESI Act allows for maternity benefits to be provided for a specified duration in case of miscarriage. According to the Act, in the event of a miscarriage, a female employee is entitled to maternity benefit for a period of 30 days.

## Why Each Wrong Option is Incorrect
- **Option A:** 20 days. This is incorrect because the specified duration for maternity benefit in case of a miscarriage under the ESI Act is not 20 days.
- **Option B:** 45 days. This is incorrect because, although it seems reasonable, the Act specifically allows for 30 days of maternity benefit in case of a miscarriage, not 45 days.
- **Option D:** 60 days. This is incorrect because the duration specified by the ESI Act for maternity benefits in the case of a miscarriage is 30 days, not 60 days.

## Clinical Pearl / High-Yield Fact
A key point to remember is that under the ESI Act, maternity benefits are provided for 26 weeks (6.5 months) for a normal delivery or confinement, and for 12 weeks in the case of adoption of a child. Importantly, in case of a miscarriage, the benefit is provided for **30 days**.

## Correct Answer: C. 30 days.