The ionising power of `alpha-`particle is less compared to `alpha-`particles but their penetrating power is more.
The mass of `beta-`particle is less than the mass of `alpha`-particle.

Options

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.

Answer

B