Which of the following options results in a graph that shows exponential growth

Question

A.f(x)= 0.4(3)^x
B.f(x)= 3(0.5)^x
C.f(x)= 0.8(0.9)^x
D.f(x)= 0.9(5)^-x

Answer 1

A is the only one that has a positive base > 1
so A

Answer 2

Thank You