Assertion: Static frictional force is a self adjusting force.
Reason: Force of static friction does not depend upon the mass of the body.

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 regarding the assertion and reason about static friction, we will analyze both statements step by step.

### Step 1: Understanding the Assertion
**Assertion**: Static frictional force is a self-adjusting force.

- **Explanation**: Static friction is indeed a self-adjusting force. This means that it can vary in magnitude depending on the external forces acting on the object. For example, if a force is applied to an object at rest, static friction will increase to match that force up to a certain maximum limit (the limiting friction). If the applied force is less than this limit, the object remains at rest, and the static friction force equals the applied force.

### Step 2: Understanding the Reason
**Reason**: Force of static friction does not depend upon the mass of the body.

- **Explanation**: The force of static friction does not directly depend on the mass of the object. Instead, it depends on the normal force acting on the object, which is often related to the mass when on a horizontal surface (normal force = weight = mg). However, in cases where the normal force is altered (e.g., an object pressed against a wall), the static friction can still act without being directly dependent on the mass.

### Step 3: Analyzing the Relationship
- The assertion is true because static friction adjusts to prevent motion.
- The reason is also true, but it does not provide a complete explanation for the assertion. While the static friction force does not depend solely on mass, it is influenced by the normal force, which is often related to mass.

### Conclusion
Both the assertion and reason are correct, but the reason does not correctly explain the assertion. Therefore, the correct answer is that both statements are true, but the reason is not the correct explanation for the assertion.

### Final Answer
- **Assertion**: True
- **Reason**: True, but not the correct explanation for the assertion.

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