How is an exponential growth function of the form ​f(x) related to an exponential function of the form ​f(x)​? Choose the correct answer below. A. The value of a is the initial​ amount, and b is equal to the growth factor ​(1​r). B. The value of a is the growth​ factor, and b is equal to the initial amount ​(1​r). C. The value of a is the initial​ amount, and b is equal to the growth factor r. D. The value of a is the growth​ factor, and b is equal to the initial amount r.