In a graph of population, on x-axis time and on y-axis population is plotted. A parallel line to x-axis shows:

Options

A. Natality equal to mortality
B. Natality decreases mortality increases
C. Natality constant mortality increases
D. Natality increases mortality decreases

Answer

To solve the question regarding the interpretation of a parallel line to the x-axis in a population graph, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding the Axes**:
- The x-axis represents time.
- The y-axis represents population.

2. **Drawing the Graph**:
- Imagine a graph where the x-axis is horizontal (time) and the y-axis is vertical (population).
- A line that is parallel to the x-axis indicates that the population remains constant over time.

3. **Analyzing the Parallel Line**:
- A line parallel to the x-axis means that as time progresses (moving along the x-axis), the population does not change (the value on the y-axis remains the same).

4. **Interpreting the Meaning**:
- When the population is constant over time, it indicates that the number of individuals in the population is stable.
- This stability occurs when the birth rate (natality) is equal to the death rate (mortality).

5. **Conclusion**:
- Therefore, the condition represented by a parallel line to the x-axis in this population graph indicates that the birth rate is equal to the death rate.

### Final Answer:
The correct interpretation of a parallel line to the x-axis in a population graph is that the birth rate is equal to the death rate.