Assertion : Intensity of X-rays can be controlled by adjusting the filament current and voltage. Reason : The intensity of X-rays does not depend on number of X-ray photons emitted per second from the target.

• 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.