## Core Concept
The reproductive age group for women is generally considered to be between 15 and 49 years. This age range is crucial for demographic and health statistics, including fertility rates and population growth. The percentage of women in this age group can vary depending on the population's age structure.

## Why the Correct Answer is Right
The correct answer indicates a specific percentage of women in the reproductive age group. Although the actual percentage can vary by country and region due to differences in population demographics, a commonly cited figure for the proportion of women of reproductive age (15-49 years) in many populations is around 20%. This figure can be derived from population pyramids and demographic data.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is incorrect because it does not accurately reflect the commonly known percentage of women in the reproductive age group.
- **Option B:** Similarly, this option does not match the expected demographic data for women of reproductive age.
- **Option D:** This option is also incorrect as it does not align with the typical demographic distribution.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the reproductive age group (15-49 years) is significant for public health, especially for family planning, maternal health services, and estimating fertility rates. Knowing the approximate percentage of women in this age group can help in planning healthcare services.

## Correct Answer Line
**Correct Answer: C. 20%**