Assertion: In and elastic collision of two billiard balls, the total kinetic energy is conserved during the short time of collision of balls.Reason: Energy spent against friction does not follow the law of conservation of energy

• A. Both assertion and reason are true and the reason is the correct explanation of the assertion
• B. Both assertion and reason are true but the reason is not the correct explanation of the assertion
• C. Both assertion and reason are false
• D. Assertion is true but the reason is false