Assertion : Soft and hard X-rays differ in frequency as well as velocity. Reason : The penetrating power of hard X-rays is more than the penetrating power of soft X-rays.

• 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.