Which of the following choices describes the function f(x)=(x^2-5)? A. parabola opens upward; vertex (0, 0); line of symmetry is x=0
B. parabola opens upward; vertex (1, 5); line of symmetry is x=1
C. parabola opens upward; vertex (0, -5); line of symmetry is x=-5
D. None of these choices are correct.