A population is said to achieve demographic transition, if

Options

A. Birth rate equals death rate
B. Emigration equals immigration if population is same, in both places
C. Doubling time is 33 years
D. Both (1) & (2)

Explanation

To answer the question "A population is said to achieve demographic transition, if...", we need to understand the concept of demographic transition and the stages it involves.

### Step-by-Step Solution:

1. **Understanding Demographic Transition**:
- Demographic transition refers to the transition of a population from high birth and death rates to low birth and death rates as a country develops economically.

2. **Stages of Demographic Transition**:
- There are typically four or five stages in demographic transition:
- **Stage 1**: High birth and death rates, leading to a stable population.
- **Stage 2**: Death rates drop due to improvements in healthcare and sanitation, while birth rates remain high, leading to population growth.
- **Stage 3**: Birth rates begin to decline as a result of changes in social values and access to contraception, leading to a slowing population growth.
- **Stage 4**: Both birth and death rates are low, stabilizing the population.
- **Stage 5** (sometimes included): Birth rates fall below death rates, leading to a potential decrease in population.

3. **Criteria for Achieving Demographic Transition**:
- A population is said to achieve demographic transition when it moves from Stage 1 to Stage 4 or 5, characterized by low birth and death rates, resulting in a stable or declining population.

4. **Conclusion**:
- Therefore, a population achieves demographic transition when it successfully shifts from high birth and death rates to low birth and death rates, stabilizing the population growth.