The number of new individuals produced in a unit time, per unit population is described as

Options

A. Mortality
B. Natality
C. Immigration
D. Emigration

Answer

To solve the question, "The number of new individuals produced in a unit time, per unit population is described as," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Terms**:
- We need to identify what is meant by "new individuals produced" in a population context. This usually refers to the birth of new individuals.

2. **Identifying the Options**:
- The options provided are:
1. Mortality
2. Natality
3. Immigration
4. Emigration

3. **Analyzing Mortality**:
- Mortality refers to the death rate in a population, which is the number of individuals dying in a unit time per unit population. This does not relate to the production of new individuals.

4. **Analyzing Natality**:
- Natality is defined as the birth rate, which is the number of new individuals produced in a unit time per unit population. This directly corresponds to the question.

5. **Analyzing Immigration**:
- Immigration refers to the number of individuals moving into a population from outside. This is not about new individuals being produced within the population.

6. **Analyzing Emigration**:
- Emigration is the number of individuals leaving a population. Similar to immigration, this does not pertain to the production of new individuals.

7. **Conclusion**:
- After analyzing all the options, the term that best fits the description of "the number of new individuals produced in a unit time, per unit population" is **Natality**.

### Final Answer:
The correct answer is **Natality**.