## Core Concept
The sex ratio in a population is defined as the number of females per 1000 males. It is an important demographic indicator that reflects the balance between the sexes in a given area. The sex ratio can vary significantly due to factors like gender-selective abortion, differential mortality rates, and migration patterns.

## Why the Correct Answer is Right
The correct sex ratio as per the 2011 census of India is 940 females per 1000 males. This figure is derived from the actual enumeration of the population during the 2011 census. It reflects a complex interplay of sociocultural, economic, and healthcare factors influencing the population's gender balance.

## Why Each Wrong Option is Incorrect
- **Option A:** 881 - This figure does not match the 2011 census data for India's sex ratio.
- **Option B:** 927 - Although close, this is not the correct figure for the 2011 census.
- **Option D:** 958 - This option also does not accurately represent the sex ratio according to the 2011 census.

## Clinical Pearl / High-Yield Fact
A lower sex ratio often indicates a preference for male children, leading to practices like female feticide or neglect, which can have significant social and economic implications. India's sex ratio has been a focus of policy interventions aimed at addressing these issues.

## Correct Answer Line
**Correct Answer: C. 940**