**Core Concept**
The given question pertains to the measurement of fertility, specifically the total fertility rate (TFR), which is a key indicator of a population's reproductive health. TFR is defined as the average number of live births a woman would have in her lifetime based on the current age-specific fertility rates of a population.

**Why the Correct Answer is Right**
The correct answer represents the total fertility rate (TFR), which is a demographic measure used to express the average number of children a woman would have in her lifetime based on the age-specific fertility rates of a population. TFR takes into account the age-specific fertility rates of women in the reproductive age group (usually 15-49 years) and calculates the average number of live births per woman over her lifetime. This measure provides valuable insights into fertility trends and population growth.

**Why Each Wrong Option is Incorrect**
**Option A:** This option represents a measure of fertility that is not a valid demographic indicator. Fertility rate is a term often confused with total fertility rate; however, fertility rate is a more general term that can refer to various measures of fertility.

**Option B:** This option is incorrect because it represents the general fertility rate (GFR), which is the number of live births per 1,000 women of reproductive age (usually 15-49 years). While GFR is an important fertility measure, it does not account for the age structure of the population.

**Option C:** This option is also incorrect because it represents the crude birth rate (CBR), which is the number of live births per 1,000 people in a population. CBR does not account for the age structure of the population and is not a direct measure of fertility.

**Clinical Pearl / High-Yield Fact**
When analyzing fertility trends, it's essential to consider the total fertility rate (TFR) as a more comprehensive measure of fertility than the general fertility rate or crude birth rate. TFR takes into account the age-specific fertility rates of women in the reproductive age group, providing a more accurate picture of fertility trends.

**Correct Answer: D. 220**