Assertion: Pseudo force is an imaginary force which is recongnised only by a non-inertial observer to explain the physical situation according to newton's laws.
Reason: Pseudo force has no physical origin, that is it is not caused by one of the basic interactions in nature. It does not exist in the action-reaction pair.

Options

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

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understand the Assertion
The assertion states that a pseudo force is an imaginary force recognized only by a non-inertial observer to explain physical situations according to Newton's laws.

**Explanation**:
- A pseudo force is indeed considered an imaginary force because it is not a real force acting on an object but is introduced to account for the effects of acceleration in a non-inertial frame of reference.
- Non-inertial frames are those that are accelerating, and in such frames, observers perceive forces that do not exist in inertial frames.

### Step 2: Understand the Reason
The reason states that pseudo force has no physical origin; it is not caused by one of the basic interactions in nature and does not exist in the action-reaction pair.

**Explanation**:
- Pseudo forces arise due to the acceleration of the reference frame and are not due to any physical interaction (like gravitational, electromagnetic, etc.).
- In Newton's third law, every action has an equal and opposite reaction. Since pseudo forces are not real forces, they do not have a corresponding reaction force.

### Step 3: Analyze the Relationship Between Assertion and Reason
Now, we need to determine if the reason correctly explains the assertion.

- The assertion is true: pseudo forces are indeed imaginary and recognized by non-inertial observers.
- The reason is also true: pseudo forces do not have a physical origin and do not exist in action-reaction pairs.

However, while both statements are true, the reason does not provide a correct explanation for the assertion. The assertion focuses on the necessity of pseudo forces in non-inertial frames, while the reason discusses their lack of physical origin and absence in action-reaction pairs, which is not directly related to why they are used.

### Conclusion
- **Assertion**: True
- **Reason**: True
- **Explanation**: The reason does not correctly explain the assertion.

Thus, the correct answer is that the assertion is true, and the reason is true, but the reason is not the correct explanation for the assertion.

### Final Answer
Assertion is true, Reason is true, but Reason is not the correct explanation for Assertion.

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