Sex Ratio:
Sex ratio refers to the number of females per 1000 males in a given population. It is a demographic indicator that provides insights into the gender distribution within a society or a specific geographic area. The sex ratio is often used to understand the balance between males and females in a population and to analyze the social, economic, and cultural implications of this distribution.

Explanation:
The correct answer is option 'B' - the sex ratio represents the number of females per 1000 males. This means that for every 1000 males in a population, the sex ratio tells us the number of females present. Let's delve deeper into the explanation of this answer.

Understanding the Calculation:
The sex ratio is calculated by dividing the number of females by the number of males in a population and multiplying the result by 1000. This provides a standardized measure that allows for comparison between different populations or regions.

Interpreting the Result:
The resulting value of the sex ratio can be greater than, equal to, or less than 1000.

- If the sex ratio is greater than 1000, it indicates a higher proportion of females compared to males in the population.
- If the sex ratio is equal to 1000, it suggests an equal number of males and females in the population.
- If the sex ratio is less than 1000, it implies a higher proportion of males compared to females in the population.

Significance of Sex Ratio:
The sex ratio holds significant sociocultural, economic, and demographic implications. Here are some key points to understand its significance:

1. Gender Imbalance: The sex ratio helps identify gender imbalances in a population. A higher sex ratio can indicate factors such as sex-selective practices, gender discrimination, or migration patterns.

2. Social and Economic Implications: An imbalanced sex ratio can impact the social fabric and economic dynamics of a society. It can lead to issues like increased competition for marriage partners, increased crime rates, and social unrest.

3. Health and Development: The sex ratio can reflect the overall health and development status of a population. A skewed sex ratio may be indicative of issues like maternal mortality, gender-based violence, or inadequate healthcare facilities.

4. Policy Planning: Governments and policymakers use sex ratio data to develop appropriate policies and interventions to address gender disparities, promote gender equality, and ensure the well-being of the population.

Conclusion:
In conclusion, the sex ratio represents the number of females per 1000 males in a given population. It is a crucial demographic indicator that helps analyze gender imbalances, societal dynamics, and development issues. By understanding the sex ratio, policymakers can formulate effective strategies to address gender disparities and promote gender equality.