**Core Concept**
The general fertility rate (GFR) is a demographic measure that assesses the number of births per 1,000 women of reproductive age (usually 15-44 years) in a given population. It is a crucial indicator of fertility trends and reproductive health.

**Why the Correct Answer is Right**
The correct denominator for the general fertility rate is the number of women of reproductive age in the population. This is because the GFR is calculated by dividing the number of births by the total number of women in the reproductive age group. This allows for a standardized comparison of fertility rates across different populations. The reproductive age group is defined as the age range during which women are capable of becoming pregnant, typically between 15 and 44 years.

**Why Each Wrong Option is Incorrect**
**Option A:** is incorrect because it refers to the crude birth rate, which is the total number of births per 1,000 people in the population, regardless of age.

**Option B:** is incorrect because it refers to the total fertility rate, which is the average number of children a woman would have in her lifetime based on the current age-specific fertility rates of a population.

**Clinical Pearl / High-Yield Fact**
To remember the denominator for the general fertility rate, recall that it is based on the number of women in the reproductive age group, which is a critical factor in assessing fertility trends.

**Correct Answer: C. Women of reproductive age.**