Which of the following is not an example of non periodic changes?

Options

A. Falling sick
B. A road accident
C. Dust storm
D. Change of seasons

Explanation

To determine which of the following is not an example of non-periodic changes, we need to understand the definitions of periodic and non-periodic changes.

### Step-by-Step Solution:

1. **Understand Periodic Changes**:
- Periodic changes are those that occur at regular intervals of time. For example, the change of seasons happens every year, which is a fixed interval (365 days).

2. **Understand Non-Periodic Changes**:
- Non-periodic changes occur irregularly and do not follow a fixed time interval. For instance, falling sick can happen at any time and is not predictable.

3. **Analyze the Options**:
- Let's consider the options provided:
- **Falling Sick**: This is non-periodic because it does not happen at regular intervals.
- **Road Accident**: This is also non-periodic as accidents can occur at any time without a fixed schedule.
- **Dust Storm**: Similar to the above, dust storms occur unpredictably and are non-periodic.
- **Change of Season**: This is periodic because it happens at regular intervals (every year).

4. **Identify the Correct Answer**:
- Since the question asks for the option that is not an example of non-periodic changes, we find that the change of season is the only periodic change among the options given.

5. **Conclusion**:
- Therefore, the answer to the question is that the change of season is not an example of non-periodic changes.

### Final Answer:
The change of season is not an example of non-periodic changes.