Which of the following pairs contributes to an increase in population ?

Options

A. Emigration and natality
B. Natality and immigration
C. Mortality and emigration
D. Immigration and mortality

Answer

To solve the question "Which of the following pairs contributes to an increase in population?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Population Dynamics**:
- Population dynamics involves studying how populations change over time, which includes factors that increase or decrease population size.

2. **Identifying Key Terms**:
- **Natality (B)**: This refers to the total number of births in a population over a specific time period. An increase in natality means more individuals are being added to the population.
- **Immigration (I)**: This is the arrival of individuals from other areas into the population's habitat. Immigration increases the number of individuals in the population.

3. **Recognizing Decreasing Factors**:
- **Mortality (D)**: This refers to the number of deaths in a population over a given time period. An increase in mortality decreases the population size.
- **Emigration (E)**: This is the movement of individuals out of the population to other habitats. Emigration also decreases the population size.

4. **Combining the Factors**:
- To determine which pairs contribute to an increase in population, we focus on natality and immigration. Both of these factors lead to an increase in the number of individuals in the population.

5. **Conclusion**:
- The correct answer to the question is the pair consisting of **Natality and Immigration**. This means that the option that includes these two factors is the right answer.

### Final Answer:
- The pair that contributes to an increase in population is **Natality and Immigration**.

---