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. 3/4th of it will disintegrate in two months
B. It will completely disintegrate in two months
C. It will completely disintegrate in four months
D. 1/8th of it will remain intact at the end of four months