**Core Concept**
The question is testing the concept of the **Crude Birth Rate (CBR)**, which is a demographic measure used to express the number of live births per 1,000 women of reproductive age (usually 15-49 years) in a given area or population over a specific time period, typically one year.

**Why the Correct Answer is Right**
The CBR is an important indicator of fertility and reproductive health in a population. It takes into account the number of live births, but not the number of deaths or population growth, making it a useful measure for comparing fertility rates across different areas or populations. The CBR is usually calculated using the formula: CBR = (Number of live births x 1,000) / (Population of women of reproductive age x Time period).

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the correct unit of measurement (per 1,000 women of reproductive age).
**Option B:** This option is incorrect because it does not provide a specific number, making it an incomplete answer.
**Option C:** This option is incorrect because it is a different demographic measure (Crude Death Rate) that expresses the number of deaths per 1,000 population, not live births.

**Clinical Pearl / High-Yield Fact**
The CBR is an important indicator of a population's fertility and reproductive health, and it can be influenced by various factors such as access to family planning services, education, and economic status.

**Correct Answer: D. 120-140.**