A radioactive material of half-life `T` was kept in a nuclear reactor at two different instants. The quantity kept second time was twice of the kept first time. If now their present activities are `A_1` and `A_2` respectively, then their age difference equals
A. `(T)/(ln2)|ln.(2A_(1))/(A_(2))|`
B. `T|ln.(2A_(1))/(A_(2))|`
C. `(T)/(ln2)|ln.(A_(1))/(2A_(2))|`
D. `T|ln.(A_(2))/(2A_(1))|`
