Assorsion : A positive acceleration can be associated with a 'slowing down' of the body.
Reason : The origin and the positive direction of an axis are a matter of choice.

Options

A. A.If both assertion`&` reason are True `&` the Reason is a corrrect explanation of the Asserion.
B. B.If both Assertion `&` Reason are True but Reason is not correct explanation of the Assertion.
C. C.If Assertion is Trie but the Reason is False.
D. D.If both Assertion `&` Reason are false

Answer

To solve the assertion and reason question, we will analyze both the assertion and the reason step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "A positive acceleration can be associated with a 'slowing down' of the body."
- To analyze this, we need to consider the relationship between acceleration and velocity.

2. **Analyzing Acceleration and Velocity**:
- Acceleration is defined as the rate of change of velocity. If acceleration is positive, it typically means that the velocity of the body is increasing in the positive direction.
- However, if the velocity of the body is in the negative direction (opposite to the positive acceleration), the body will indeed slow down.

3. **Example Case**:
- Let's assume we define the positive direction as to the right. If the velocity of the body is to the left (negative) and the acceleration is to the right (positive), the body will slow down because the acceleration is acting against the direction of velocity.

4. **Understanding the Reason**:
- The reason states that "The origin and the positive direction of an axis are a matter of choice."
- This means that the definitions of positive and negative directions are arbitrary and can be defined based on the context of the problem.

5. **Conclusion**:
- Since we have established that a positive acceleration can indeed lead to a slowing down of the body when the velocity is in the opposite direction, the assertion is true.
- The reason is also true because the choice of direction does not affect the fundamental physics of motion.
- Therefore, both the assertion and reason are correct, and the reason provides a correct explanation for the assertion.

### Final Answer:
Both the assertion and reason are true, and the reason correctly explains the assertion.