For this case we have a function of the form:

Where 
The domain of that function is given by all the values that x can take.
If b is a positive real number other than 1 and a> 0, we have that the domain of f (x) is given by (-∞,∞). x can take any value.
On the other hand, the range is given by the dependent values of the variable "y".
IF we evaluate f (-∞) then y tends to zero.
If we evaluate f (∞) then y tends to infinity.
Thus, the range is: (0, ∞)
So, we have:
Domain: (-∞,∞)
Range: (0, ∞)
Answer:
Option C