Answer:
Option 4.
Explanation:
In option 4, we find the function at the different values of x as
x -1 0 1 2 3
f(x) 1/2 1 2 4 8
We find the common ration in each value of f(x) is = 2/1 =2
Rest all the tables don't represent the relationship of an exponential sequence.
Therefore option 4 is the answer.