A. f(x)=4*2^x b. f(x)=0.5*(4)^x c. f(x)=2*(0.5)^x d. f(x)=4*(0.5)^x

ANSWER
The answer is D



EXPLANATION

Let the exponential function be of the form



Each box on both the x and y axes is one unit.

The graph passes through the point .

This point must satisfy the equation above.



This implies that,





The function now becomes,



The graph also passes through



We substitute this point too to get,



This implies that,







or



We substitute back to get,



The correct answer is D.

I'm sure the answer is a