The population p(t) at time t of a certain mouse species satisfies the
differential equation `(d p(t)/(dt)=0. 5 p(t)-450`
If `p(0)""=""850`
, then the time at which the population becomes zero is
(1) 2 ln 18 (2) ln
9 (3) `1/2`
In 18 (4) ln 18
A. `2.log18`
B. `log9`
C. `(1)/(2).log18`
D. `log18`