Assertion: In a perfectly inelastic collision in the absence of external forces , the kinetic energy is never conserved.
Reason: The objects deformed and stick together in this type of collision.

Options

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

Explanation

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

### Step 1: Understanding the Assertion
The assertion states that "In a perfectly inelastic collision in the absence of external forces, the kinetic energy is never conserved."

- In a perfectly inelastic collision, two objects collide and stick together after the collision.
- During this type of collision, some of the kinetic energy is transformed into other forms of energy (like heat, sound, or deformation energy), which means that the total kinetic energy after the collision is less than it was before the collision.

**Conclusion for Step 1:** The assertion is true.

### Step 2: Understanding the Reason
The reason states that "The objects deformed and stick together in this type of collision."

- In a perfectly inelastic collision, indeed, the objects do deform upon impact and stick together. This deformation is a result of the collision and contributes to the energy transformation mentioned in the assertion.
- However, while the reason is true, it does not explain why kinetic energy is not conserved. The deformation and sticking together are consequences of the collision, but they do not directly relate to the conservation of kinetic energy.

**Conclusion for Step 2:** The reason is true, but it does not correctly explain the assertion.

### Final Conclusion
Both the assertion and the reason are true, but the reason is not the correct explanation of the assertion. Therefore, the correct answer is that both statements are true, but the reason does not provide a valid explanation for the assertion.