Nuclei of radioactive element `A` are produced at rate `t^(2)` (where `t` is time) at any time `t`. The element `A` has decay constant `lambda`. Let `N` be the number of nuclei of element `A` at any time `t`. At time `t=t_(0), dN//dt` is minimum. The number of nuclei of element `A` at time `t=t_(0)` is
A. `(2t_(0)-lambdat_(0)^(2))/lambda^(2)`
B. `(t_(0)-lambdat_(0)^(2))/lambda^(2)`
C. `(2t_(0)- lambdat_(0)^(2))/lambda`
D. `(t_(0)-lambdat_(0)^(2))/lambda`