The amount of radioactive material changes with time. The table below shows the amount of radioactive material f(t) left after time t:
t(hours) 0 1 2
f(t) 100 50 25
Which exponential function best represents the relationship between f(t) and t?
f(t)= 0.5(100)^t

f(t)= 100(0.25)^t

f(t)=0.25(50)^t

f(t)= 100(0.5)^t