Answer:
A.
The graph gets closer to the x-axis.
Explanation:
We are given an exponential function:

Now we know that if a number lies between 0 and 1 and as we keep on increasing its power the number goes on decreasing and ultimately it tends to zero
Here, b lies between 0 and 1 so, as we keep on increasing the power of b it will tend to zero
i.e.
tends to zero
Hence,
tends to zero
i.e. The graph gets closer to the x-axis.
Hence, A is the correct option