Assertion : When a bicycle is in motion, the force of friction exerted by the ground on the two wheels is always in forward direction. Reason : The frictional force acts only when the bodies are in contact.

• 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 the assertion and reason both are false.   
• E.    If assertion is false but reason is true.