Assertion : Inertia is the property by virtue of which the body is unable to change by itself the state of rest only.
Reason : The bodies do not change their state unless acted upon by an unbalanced external force.

Options

A. If both assertion and reason are true and the reason is the correct explanation of the assertion
B. If both assertion and reason are true but reason is not the correct explanation of the assertion
C. If assertion is true but reason is false.
D. If assertion is fa lse but reason is true.

Answer

To analyze the assertion and reason provided in the question, we need to break down both statements and evaluate their validity.

### Step 1: Understanding the Assertion
The assertion states: "Inertia is the property by virtue of which the body is unable to change by itself the state of rest only."

- Inertia is indeed a property of matter that describes its resistance to changes in its state of motion. However, it applies to both states of rest and motion. A body at rest will remain at rest, and a body in motion will continue to move at a constant velocity unless acted upon by an external force. Therefore, the assertion is **incorrect** because it limits inertia to only the state of rest.

### Step 2: Understanding the Reason
The reason states: "The bodies do not change their state unless acted upon by an unbalanced external force."

- This statement is a correct interpretation of Newton's First Law of Motion. It states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. This means that both bodies at rest and bodies in motion will not change their state without an external force. Thus, the reason is **correct**.

### Step 3: Conclusion
- Since the assertion is incorrect and the reason is correct, we conclude that the assertion does not support the reason.

### Final Answer:
- The assertion is **false** and the reason is **true**. Therefore, the correct relationship is that the assertion does not logically follow from the reason.

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