Answer:
The correct option is C.
Explanation:
The general exponential function is

Where, a is initial value and b is growth factor.
The given function is

Here
, therefore it is a decay function. In other words, the given function always decreases.
The given function is defined for all real numbers, therefore the domain of the function is all real number.
Put x=0, to find the y-intercept.

The y-intercept of the function is at (0,1). Therefore option C is correct.


Therefore the range of the function is y>0.