Assume that a is a real number such that the quadratic function f (x) = ax 2 + 100 does not have a maximum value. Which of the following quadratic functions has a maximum value? A. p(x) = (a + 100)x2 + 100 O B. g(x) = ( )x2 + 100 O C. h(x) = a 2x2 + 100 O D. g(x) = -ax2 + 100