Assertion : The ionising power of b-particle is less compared to a-particles but their penetrating power is more. Reason : The mass of b-particle is less than the mass of a-particle.

• 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.