The half life period of a radioactive substance is best determined by counting the number of alpha particles emitted per second in a Geiger Muller counter from its known quantity. If the half life period of a radioactive substance is one month, then

A. $${\frac{3}{4}^{{\text{th}}}}$$ of it will disintegrate in two months

B. It will completely disintegrate in two months

C. It will completely disintegrate in four months

D. $${\frac{l}{8}^{{\text{th}}}}$$ of it will remain intact at the end of four months

Answer: Option B