If f(x) 2x2 8x 9, which statement regarding the vertex form of f(x) is true? a. in vertex form, f(x) 2(x 2)2 1 and therefore has a minimum value of 1 b. in vertex form, f(x) 2 (x 2)2 1 and therefore has a minimum value of 2. c. in vertex form, f(x) 2(x 2)2 4.5 and therefore has a minimum value of 4.5 d. in vertex form, f(x) 2(x 2)2 4.5 and therefore has a minimum value of 2.