A radioactive nucleus can decay by two different processes. The half life for the first process is `2 t` and that for the second process is `t`. The effective disintergration constant of nucleus is
A. `(3)/(2t l n)`
B. `(3 l n2)/(2t)`
C. `( l n2)/(3t)`
D. `(3 l n2)/(t)`