The standard form for an exponential function is [tex]y=a(b)^x[/tex] where is the initial value and b is the growth factor. If b > 1, then it is an exponential growth function, and if 0 < b < 1, then it is an exponential decay function. The b values that are greater than 1 are in A and C. The b values in B and D are greater than 0 but are less than 1 so those are decay. A and C are your answers.