A radioactive isotope having a half life of 3 days was received after 12 days. It was found that there were 3 gm of the isotopes in the container. The initial weight of the isotope when packed was
a)12 gm
b)24gm
c)36 gm
d)48 gm
A. 48 g
B. 36 g
C. 24 g
D. 12 g